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Top Foods Rich in Vitamin D

• Protein Sources
• Fruits and Vegetables
• Dairy and Non-Dairy Sources
• Daily Requirement
• Fortified Foods Debate
• While Food Sources
• Vitamin D Deficiency

Vitamin D is an essential micronutrient that helps your body to absorb calcium , which protects the health of your bones and teeth. It also reduces inflammation, regulates blood sugar, increases phosphate absorption, prevents muscle weakness and spasms, and boosts the body’s natural immune response. Our bodies produce vitamin D in response to ultraviolet (UV) radiation from the sun. But in the U.S., many people don’t get enough vitamin D from sunlight. 

Foods rich in vitamin D include fatty fish, fish liver oils, beef liver, and egg yolks, among others. Other foods, such as milk and breakfast cereal, are often fortified with vitamin D – meaning that it is added to them during manufacturing.  

Learn more about foods that contain vitamin D, including proteins, fruits and vegetables, dairy products, and more.

Malcolm P Chapman / Getty Images

Protein Rich in Vitamin D

Oily, fatty fish are one of the best food sources of vitamin D. Examples of proteins that are rich in vitamin D include:

Fruits and Vegetables Rich in Vitamin D

Generally, fruits and vegetables don’t provide any vitamin D. 

Still, certain fungi, such as reindeer lichen and mushrooms, absorb vitamin D through exposure to UV radiation during growth. Raw shiitake, chanterelle, and oyster mushrooms are particularly rich sources of vitamin D.

Dairy (and Non-Dairy) Rich in Vitamin D

Dairy and egg products are another common source of vitamin D. Some, like cow’s milk, are typically fortified with vitamin D, while it occurs naturally in others, such as butter and cheese. 

Examples include:

• Whole eggs (specifically egg yolks )

Other Sources of Vitamin D

Outside of meat, dairy products, and fruits and vegetables, other edible sources of vitamin D include:

• Fish liver oils, such as cod liver oil – one of the top sources of vitamin D
• Dark chocolate

How Much Vitamin D Should You Get Daily?

According to the U.S. Food and Drug Administration (FDA), the recommended daily intake of vitamin D is as follows (listed in both International Units and micrograms):

• 0-12 months old: 10 mcg/400 IU
• 1-13 years old: 15 mcg/600 IU
• 14-18 years old: 15 mcg/600 IU
• 19-70 years old: 15 mcg/600 IU
• 71+ years old: 20 mcg/800 IU
• Pregnant or breastfeeding: 15 mcg/600 IU

Debate on Fortified Foods Rich in Vitamin D

In addition to some of the dairy products listed above, many other foods are fortified with vitamin D. Typically, these include:

• Almond milk
• Breakfast cereals
• Orange juice

Many foods are fortified with vitamin D because of the relatively few foods that have naturally high amounts of it. Some clinicians argue that this is beneficial in preventing vitamin D deficiency and increasing the vitamin D intake in the general population, particularly among people with food allergies and those who follow vegan or vegetarian diets. 

However, the practice is somewhat controversial. Some researchers have argued that eating fortified foods may lead to excessive vitamin D intake, known as vitamin D toxicity . Signs of vitamin D toxicity include:

• Reduced appetite
• Unintended weight loss
• Constipation
• Muscle weakness

Consuming too much vitamin D may also lead to hypercalcemia (very high levels of calcium in the blood). Over time, hypercalcemia may lead to complications such as:

• Kidney failure
• Disorientation
• Arrhythmia (irregular heartbeat)

Getting Vitamin D From Whole Foods

Because most whole foods don’t contain much vitamin D without the help of fortification, many people take in vitamin D primarily through sun exposure.

However, excessive sun exposure can also lead to health complications like sunburn and skin cancer . If you think you may be at risk for vitamin D deficiency, your healthcare provider may recommend that you take a daily vitamin D supplement to lower your risk.

Vitamin D Supplements

If you are at risk for vitamin D deficiency, Vitamin D supplements may help to prevent any complications. Risk factors for vitamin D deficiency include:

• Spending a lot of time indoors
• Living in a cold climate
• Having dark skin
• Being 65 years old or older
• Eating a plant-based diet, such as a vegan or vegetarian diet
• Allergies to foods that typically contain vitamin D
• Having had gastric bypass surgery
• Chronic kidney or liver disease
• Crohn’s disease
• Ulcerative colitis  
• Celiac disease
• Taking certain medications, such as anti-seizure and cholesterol-lowering medications

Am I Getting Enough Vitamin D From My Diet?

If left untreated, a deficiency in vitamin D can lead to a number of health complications. These include:

• Rickets , a disorder that causes bone deformities in children
• Osteoporosis , a condition caused by bone loss and reduced bone density
• Osteomalacia , a “bone softening” disorder that primarily affects adults
• Muscle spasms

Vitamin D deficiency typically doesn’t cause many symptoms at first. The main way to tell if you have a vitamin D deficiency is through a blood test from your healthcare provider.

People can get vitamin D from sunlight, food, and supplements. Food sources of vitamin D include fatty fish and fish liver oils, beef liver, egg yolks, cheese, and mushrooms. Certain foods, like cow’s milk, non-dairy milk, breakfast cereals, and orange juice, are also frequently fortified with vitamin D. 

Let your healthcare provider know if you’re not sure you’re getting enough vitamin D each day. They can recommend dietary sources of vitamin D or prescribe a high-dose supplement if needed.

National Health Service. Vitamin D .

National Institutes of Health - Office of Dietary Supplements. Vitamin D - fact sheet for health professionals .

National Institutes of Health: Office of Dietary Supplements.  Omega-3 fatty acids: Fact sheet for health professionals .

Dominguez LJ, Farruggia M, Veronese N, Barbagallo M. Vitamin D sources, metabolism, and deficiency: Available compounds and guidelines for its treatment . Metabolites . 2021;11(4):255. doi:10.3390/metabo11040255

Cardwell G, Bornman JF, James AP, Black LJ. A review of mushrooms as a potential source of dietary vitamin D . Nutrients . 2018;10(10):1498. doi:10.3390/nu10101498. PMID: 30322118; PMCID: PMC6213178

Benedik E. Sources of vitamin D for humans . Int J Vitam Nutr Res . 2022;92(2):118-125. doi:10.1024/0300-9831/a000733

National Institutes of Health - Office of Dietary Supplements. Vitamin D - fact sheet for consumers .

Adebayo FA, Itkonen ST, Öhman T, et al. Safety of vitamin D food fortification and supplementation: Evidence from randomized controlled trials and observational studies . Foods . 2021;10(12):3065. doi:10.3390/foods10123065

MedlinePlus. Vitamin D deficiency .

MedlinePlus. Vitamin D .

By Laura Dorwart Dr. Dorwart has a Ph.D. from UC San Diego and is a health journalist interested in mental health, pregnancy, and disability rights.

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Vitamin D is a nutrient your body needs for building and maintaining healthy bones. That's because your body can only absorb calcium, the primary component of bone, when vitamin D is present. Vitamin D also regulates many other cellular functions in your body. Its anti-inflammatory, antioxidant and neuroprotective properties support immune health, muscle function and brain cell activity.

Vitamin D isn't naturally found in many foods, but you can get it from fortified milk, fortified cereal, and fatty fish such as salmon, mackerel and sardines. Your body also makes vitamin D when direct sunlight converts a chemical in your skin into an active form of the vitamin (calciferol).

The amount of vitamin D your skin makes depends on many factors, including the time of day, season, latitude and your skin pigmentation. Depending on where you live and your lifestyle, vitamin D production might decrease or be completely absent during the winter months. Sunscreen, while important to prevent skin cancer, also can decrease vitamin D production.

Many older adults don't get regular exposure to sunlight and have trouble absorbing vitamin D. If your doctor suspects you're not getting enough vitamin D, a simple blood test can check the levels of this vitamin in your blood.

Taking a multivitamin with vitamin D may help improve bone health. The recommended daily amount of vitamin D is 400 international units (IU) for children up to age 12 months, 600 IU for people ages 1 to 70 years, and 800 IU for people over 70 years.

What the research says

Research on vitamin D use for specific conditions shows:

• Cancer. Findings on the benefits of vitamin D for cancer prevention are mixed. More studies are needed to determine whether vitamin D supplementation may reduce the risk of certain cancers.
• Cognitive health. Research shows that low levels of vitamin D in the blood are associated with cognitive decline. However, more studies are needed to determine the benefits of vitamin D supplementation for cognitive health.
• Inherited bone disorders. Vitamin D supplements can be used to help treat inherited disorders resulting from an inability to absorb or process vitamin D, such as familial hypophosphatemia.
• Multiple sclerosis. Research suggests that long-term vitamin D supplementation reduces the risk of multiple sclerosis.
• Osteomalacia. Vitamin D supplements are used to treat adults with severe vitamin D deficiency, resulting in loss of bone mineral content, bone pain, muscle weakness and soft bones (osteomalacia).
• Osteoporosis. Studies suggest that people who get enough vitamin D and calcium in their diets can slow bone mineral loss, help prevent osteoporosis and reduce bone fractures. Ask your doctor if you need a calcium and vitamin D supplement to prevent or treat osteoporosis.
• Psoriasis. Applying vitamin D or a topical preparation that contains a vitamin D compound called calcipotriene to the skin can treat plaque-type psoriasis in some people.
• Rickets. This rare condition develops in children with vitamin D deficiency. Supplementing with vitamin D can prevent and treat the problem.

Generally safe

Without vitamin D your bones can become soft, thin and brittle. Insufficient vitamin D is also connected to osteoporosis. If you don't get enough vitamin D through sunlight or dietary sources, you might need vitamin D supplements.

Safety and side effects

Taken in appropriate doses, vitamin D is generally considered safe.

However, taking too much vitamin D in the form of supplements can be harmful. Children age 9 years and older, adults, and pregnant and breastfeeding women who take more than 4,000 IU a day of vitamin D might experience:

• Nausea and vomiting
• Poor appetite and weight loss
• Constipation
• Confusion and disorientation
• Heart rhythm problems
• Kidney stones and kidney damage

Interactions

Possible interactions include:

• Aluminum. Taking vitamin D and aluminum-containing phosphate binders, which may be used to treat high serum phosphate levels in people with chronic kidney disease, might cause harmful levels of aluminum in people with kidney failure in the long term.
• Anticonvulsants. The anticonvulsants phenobarbital and phenytoin (Dilantin, Phenytek) increase the breakdown of vitamin D and reduce calcium absorption.
• Atorvastatin (Lipitor). Taking vitamin D might affect the way your body processes this cholesterol drug.
• Calcipotriene (Dovonex, Sorilux). Don't take vitamin D with this psoriasis drug. The combination might increase the risk of too much calcium in the blood (hypercalcemia).
• Cholestyramine (Prevalite). Taking vitamin D with this cholesterol-lowering drug can reduce your absorption of vitamin D.
• Cytochrome P-450 3A4 (CYP3A4) substrates. Use vitamin D cautiously if you're taking drugs processed by these enzymes.
• Digoxin (Lanoxin). Avoid taking high doses of vitamin D with this heart medication. High doses of vitamin D can cause hypercalcemia, which increases the risk of fatal heart problems with digoxin.
• Diltiazem (Cardizem, Tiazac, others). Avoid taking high doses of vitamin D with this blood pressure drug. High doses of vitamin D can cause hypercalcemia, which might reduce the drug's effectiveness.
• Orlistat (Xenical, Alli). Taking this weight-loss drug can reduce your absorption of vitamin D.
• Thiazide diuretics. Taking these blood pressure drugs with vitamin D increases your risk of hypercalcemia.
• Steroids. Taking steroid mediations such as prednisone can reduce calcium absorption and impair your body's processing of vitamin D.
• Stimulant laxatives. Long-term use of high doses of stimulant laxatives can reduce vitamin D and calcium absorption.
• Verapamil (Verelan, Calan SR). Taking high doses of vitamin D with this blood pressure drug can cause hypercalcemia, and might also reduce the effectiveness of verapamil.

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• Vitamin D: Fact sheet for health professionals. Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/. Accessed Dec. 6, 2020.
• Vitamin D: Fact sheet for consumers. Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminD-Consumer/. Accessed Dec. 6, 2020.
• Vitamin D. Natural Medicines. https://naturalmedicines.therapeuticresearch.com. Accessed Dec. 6, 2020.
• AskMayoExpert. Vitamin D deficiency. Mayo Clinic; 2017.
• Cholecalciferol. IBM Microdemex. https://www.microdemexsolutions.com. Accessed Dec. 11, 2020.
• Gold J, et al. The role of vitamin D in cognitive disorders in older adults. US Neurology. 2018; doi:10.17925/USN.2018.14.1.41.
• Sultan S, et al. Low vitamin D and its association with cognitive impairment and dementia. Journal of Aging Research. 2020; doi:10.1155/2020/6097820.
• Pazirandeh S, et al. Overview of vitamin D. https://www.uptodate.com/contents/search. Accessed Dec. 13, 2020.
• Hassan-Smith ZK, et al. 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 exerct distinct effects on human skeletal muscle function and gene expression. PLOS One. 2017; doi:10.1371/journal.pone.0170665.

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The Easiest Ways To Eat More Vitamin D in the Wintertime, From Bone Density Doctors and RDs

A dietitian validates that getting enough vitamin D can be tough at any time of year. “It’s not easy for the average American to get enough vitamin D unless they spend a significant amount of time outside, are super intentional about choosing vitamin D-containing foods consistently, or take a daily vitamin D supplement,” says Kristi Ruth , RD, CNSC, LDN, the owner of Carrots and Cookies. “It’s especially tricky during winter because we tend to spend less time outdoors and wear clothing, socks, and footwear with more coverage to stay warm .”

• Anna Lutz, MPH, RD, LDN, CEDRD-S
• Kristi Ruth, RD 1 , registered dietitian

"It’s also important to note that people with disabilities, infants, elderly populations, and other groups are at risk of low vitamin D3 production ," says Robert D. Ashley , MD, an internal medicine physician, which can lower bone density and increase the risk of bone fractures.

"Additionally, people whose cultural or religious beliefs require them to be covered from head to toe may not be able to get their vitamin D from the sun , either," adds Karl Insogna , MD, FACP, a Yale professor and internal expert in metabolic bone disease.

And while the sun can play a major role in giving us vitamin D, it’s (thankfully) not the only easy way to meet those goals. Ahead, dietitians share how to get enough vitamin D in winter—and year-round—through your diet, plus other nutritious go-tos to keep in mind regarding this all-important nutrient.

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How to get more vitamin D in winter months through your diet

Eat more fish.

In particular, Ruth lists salmon and canned tuna as options that are rich in vitamin D. “Other foods like herring, beef liver, and sardines are also notorious for being good sources of vitamin D, but may be an unrealistic recommendation for some people based on personal preference,” she adds.

Anna Lutz , MPH, RD, LDN, CEDRD-S, a dietitian with Lutz, Alexander, and Associates Nutrition Therapy, agrees that fatty fish, such as tuna and salmon, are great sources. She adds sushi is very much included here.

If you need a little extra inspiration on fishy dishes (that also aren’t too complicated), Lutz recommends mixing canned tuna with mayonnaise and pickle relish for a quick tuna salad , grabbing frozen salmon burgers at the grocery store, downing some sushi rolls, or trying the tinned fish trend .

Enjoy some eggs in all their (yellow) forms

Eggs are another natural source of vitamin D. In particular, Lutz says, it’s the egg yolk —so she encourages eating the whole egg, not just the egg whites.

Eggs can also be enjoyed at any time and in a variety of ways . Lutz says you can slice up a hard-boiled egg and put it on toast; scramble some eggs for breakfast, lunch or dinner; or put them into a delicious quiche . Regarding the latter, she adds that quiches "are easy to make with a prepared pie crust and are great as leftovers,” or suggests you “buy a prepared quiche.” Whatever fits your schedule, budget, and taste buds best.

“Not all dairy products are fortified with vitamin D, so look on the label of your yogurts and cheese for over 15 percent of your daily value of vitamin D per serving, as a general guideline." —Anna Lutz, MPH, RD, LDN, CEDRD-S

Incorporate more mushrooms

Whether you like them on your pizza, thrown in a salad, or even in chewable form, bring on the mushrooms!

Citing a study in Nutrients , Ruth shares a fun fact about how you can get even more vitamin D from them. “The more they are exposed to UV light, the more vitamin D they contain,” she says. “Some mushrooms are pre-treated with UV light, but you can also sit mushrooms out in the sun for 15 minutes to two hours to increase their vitamin D content.”

Grab some dairy products

Yogurt, milk, and cheese are typically solid options for when you need more vitamin D. In practice, this might look like a bowl of cereal and milk or a cup of yogurt.

Just be aware that some sources of dairy aren’t as beneficial in this way as others. “Not all dairy products are fortified with vitamin D, so look on the label of your yogurts and cheese for over 15 percent of your daily value of vitamin D per serving, as a general guideline,” Lutz says.

Don’t forget about vitamin D-rich breakfast foods and drinks

Cereal and orange juice, Ruth says, are often fortified with vitamin D. In fact, General Mills doubled the vitamin D count in several Big G cereals (and well-loved favorites) such as Cinnamon Toast Crunch, Honey Nut Cheerios, and Lucky Charms.

And while a glass of OJ is typically associated with breakfast, you can have it any time of day! To get the most vitamin D out of this beverage, though, Ruth recommends adding another fat source along with it.

Get enough fat sources, too

Indeed, we need more fat (and carbs) than many of us realize —and vitamin D is a fat-soluble vitamin, meaning it’s best absorbed when eaten with fat .

“Fat-free vitamin D-fortified dairy products don’t make a lot of sense, unless they are paired with another fat source,” Lutz adds.

“When fat-free foods, like orange juice, are fortified with vitamin D, you’ll want to consider eating something that contains fat for optimal absorption,” Ruth says. Examples of fat sources include avocados, nuts, and cookies, but those are only a few. She adds this isn’t usually a problem as most foods that naturally contain vitamin D also contain fat. “Mushrooms are an exception, but are often consumed with fats from salad dressing or oil when sauteed,” she clarifies. (Again, not the fat-free salad dressing—it’s a scam !)

Getting enough fat is an important reminder when you’re in the dairy aisle, too. “Fat-free vitamin D-fortified dairy products don’t make a lot of sense, unless they are paired with another fat source,” Lutz adds.

Ultimately, the main point is not to get your vitamin D from a certain place, but to get it in a way that feels right for you, your culture, and your body.

• Cardwell, Glenn et al. “A Review of Mushrooms as a Potential Source of Dietary Vitamin D.”  Nutrients  vol. 10,10 1498. 13 Oct. 2018, doi:10.3390/nu10101498

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• U.S. Department of Health & Human Services HHS
• National Institutes of Health NIH
• Division of Program Coordination, Planning, and Strategic Initiatives DPCPSI

This is a fact sheet intended for health professionals. For a general overview, see our consumer fact sheet .

For information on vitamin D and COVID-19, see Dietary Supplements in the Time of COVID-19 .

Introduction

Vitamin D (also referred to as calciferol) is a fat-soluble vitamin that is naturally present in a few foods, added to others, and available as a dietary supplement. It is also produced endogenously when ultraviolet (UV) rays from sunlight strike the skin and trigger vitamin D synthesis.

Vitamin D obtained from sun exposure, foods, and supplements is biologically inert and must undergo two hydroxylations in the body for activation. The first hydroxylation, which occurs in the liver, converts vitamin D to 25-hydroxyvitamin D [25(OH)D], also known as calcidiol. The second hydroxylation occurs primarily in the kidney and forms the physiologically active 1,25-dihydroxyvitamin D [1,25(OH)2D], also known as calcitriol [ 1 ].

Vitamin D promotes calcium absorption in the gut and maintains adequate serum calcium and phosphate concentrations to enable normal bone mineralization and to prevent hypocalcemic tetany (involuntary contraction of muscles, leading to cramps and spasms). It is also needed for bone growth and bone remodeling by osteoblasts and osteoclasts [ 1-3 ]. Without sufficient vitamin D, bones can become thin, brittle, or misshapen. Vitamin D sufficiency prevents rickets in children and osteomalacia in adults. Together with calcium, vitamin D also helps protect older adults from osteoporosis.

Vitamin D has other roles in the body, including reduction of inflammation as well as modulation of such processes as cell growth, neuromuscular and immune function, and glucose metabolism [ 1-3 ]. Many genes encoding proteins that regulate cell proliferation, differentiation, and apoptosis are modulated in part by vitamin D. Many tissues have vitamin D receptors, and some convert 25(OH)D to 1,25(OH)2D.

In foods and dietary supplements, vitamin D has two main forms, D 2 (ergocalciferol) and D 3 (cholecalciferol), that differ chemically only in their side-chain structures. Both forms are well absorbed in the small intestine. Absorption occurs by simple passive diffusion and by a mechanism that involves intestinal membrane carrier proteins [ 4 ]. The concurrent presence of fat in the gut enhances vitamin D absorption, but some vitamin D is absorbed even without dietary fat. Neither aging nor obesity alters vitamin D absorption from the gut [ 4 ].

Serum concentration of 25(OH)D is currently the main indicator of vitamin D status. It reflects vitamin D produced endogenously and that obtained from foods and supplements [ 1 ]. In serum, 25(OH)D has a fairly long circulating half-life of 15 days [ 1 ]. Serum concentrations of 25(OH)D are reported in both nanomoles per liter (nmol/L) and nanograms per milliliter (ng/mL). One nmol/L is equal to 0.4 ng/mL, and 1 ng/mL is equal to 2.5 nmol/L.

Assessing vitamin D status by measuring serum 25(OH)D concentrations is complicated by the considerable variability of the available assays (the two most common ones involve antibodies or chromatography) used by laboratories that conduct the analyses [ 5 , 6 ]. As a result, a finding can be falsely low or falsely high, depending on the assay used and the laboratory. The international Vitamin D Standardization Program has developed procedures for standardizing the laboratory measurement of 25(OH)D to improve clinical and public health practice [ 5 , 7-10 ].

In contrast to 25(OH)D, circulating 1,25(OH)2D is generally not a good indicator of vitamin D status because it has a short half-life measured in hours, and serum levels are tightly regulated by parathyroid hormone, calcium, and phosphate [ 1 ]. Levels of 1,25(OH)2D do not typically decrease until vitamin D deficiency is severe [ 2 ].

Serum concentrations of 25(OH)D and health

Although 25(OH)D functions as a biomarker of exposure, the extent to which 25(OH)D levels also serve as a biomarker of effect on the body (i.e., relating to health status or outcomes) is not clear [ 1 , 3 ].

Researchers have not definitively identified serum concentrations of 25(OH)D associated with deficiency (e.g., rickets), adequacy for bone health, and overall health. After reviewing data on vitamin D needs, an expert committee of the Food and Nutrition Board (FNB) at the National Academies of Sciences, Engineering, and Medicine (NASEM) concluded that people are at risk of vitamin D deficiency at serum 25(OH)D concentrations less than 30 nmol/L (12 ng/mL; see Table 1 for definitions of deficiency and inadequacy) [ 1 ]. Some people are potentially at risk of inadequacy at 30 to 50 nmol/L (12–20 ng/mL). Levels of 50 nmol/L (20 ng/mL) or more are sufficient for most people. In contrast, the Endocrine Society stated that, for clinical practice, a serum 25(OH)D concentration of more than 75 nmol/L (30 ng/mL) is necessary to maximize the effect of vitamin D on calcium, bone, and muscle metabolism [ 11 , 12 ]. The FNB committee also noted that serum concentrations greater than 125 nmol/L (50 ng/mL) can be associated with adverse effects [ 1 ] (Table 1).

Optimal serum concentrations of 25(OH)D for bone and general health have not been established because they are likely to vary by stage of life, by race and ethnicity, and with each physiological measure used [ 1 , 13 , 14 ]. In addition, although 25(OH)D levels rise in response to increased vitamin D intake, the relationship is nonlinear [ 1 ]. The amount of increase varies, for example, by baseline serum levels and duration of supplementation.

Recommended Intakes

Intake recommendations for vitamin D and other nutrients are provided in the Dietary Reference Intakes (DRIs) developed by expert committees of NASEM [ 1 ]. DRI is the general term for a set of reference values used for planning and assessing nutrient intakes of healthy people. These values, which vary by age and sex, include the following:

• Recommended Dietary Allowance (RDA): Average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%–98%) healthy individuals; often used to plan nutritionally adequate diets for individuals
• Adequate Intake (AI): Intake at this level is assumed to ensure nutritional adequacy; established when evidence is insufficient to develop an RDA
• Estimated Average Requirement (EAR): Average daily level of intake estimated to meet the requirements of 50% of healthy individuals; usually used to assess the nutrient intakes of groups of people and to plan nutritionally adequate diets for them; can also be used to assess the nutrient intakes of individuals
• Tolerable Upper Intake Level (UL): Maximum daily intake unlikely to cause adverse health effects

An FNB committee established RDAs for vitamin D to indicate daily intakes sufficient to maintain bone health and normal calcium metabolism in healthy people. RDAs for vitamin D are listed in both micrograms (mcg) and International Units (IU); 1 mcg vitamin D is equal to 40 IU (Table 2). Even though sunlight is a major source of vitamin D for some people, the FNB based the vitamin D RDAs on the assumption that people receive minimal sun exposure [ 1 ]. For infants, the FNB committee developed AIs based on the amount of vitamin D that maintains serum 25(OH)D levels above 20 ng/mL (50 nmol/L) and supports bone development.

Many other countries around the world and some professional societies have somewhat different guidelines for vitamin D intakes [ 15 ]. These differences are a result of an incomplete understanding of the biology and clinical implications of vitamin D, different purposes for the guidelines (e.g., for public health in a healthy population or for clinical practice), and/or the use in some guidelines of observational studies in addition to randomized clinical trials to establish recommendations [ 9 , 15 ]. The Endocrine Society states, for example, that to maintain serum 25(OH)D levels above 75 nmol/L (30 ng/mL), adults might need at least 37.5 to 50 mcg (1,500–2,000 IU)/day of supplemental vitamin D, and children and adolescents might need at least 25 mcg (1,000 IU)/day [ 11 ]. In contrast, the United Kingdom government recommends intakes of 10 mcg (400 IU)/day for its citizens age 4 years and older [ 16 ].

Sources of Vitamin D

Few foods naturally contain vitamin D. The flesh of fatty fish (such as trout, salmon, tuna, and mackerel) and fish liver oils are among the best sources [ 17 , 1 ]. An animal’s diet affects the amount of vitamin D in its tissues. Beef liver, egg yolks, and cheese have small amounts of vitamin D, primarily in the form of vitamin D 3 and its metabolite 25(OH)D 3 . Mushrooms provide variable amounts of vitamin D 2 [ 17 ]. Some mushrooms available on the market have been treated with UV light to increase their levels of vitamin D 2 . In addition, the Food and Drug Administration (FDA) has approved UV-treated mushroom powder as a food additive for use as a source of vitamin D 2 in food products [ 18 ]. Very limited evidence suggests no substantial differences in the bioavailability of vitamin D from various foods [ 19 ].

Animal-based foods typically provide some vitamin D in the form of 25(OH)D in addition to vitamin D 3 . The impact of this form on vitamin D status is an emerging area of research. Studies show that 25(OH)D appears to be approximately five times more potent than the parent vitamin for raising serum 25(OH)D concentrations [ 17 , 20 , 21 ]. One study found that when the 25(OH)D content of beef, pork, chicken, turkey, and eggs is taken into account, the total amount of vitamin D in the food is 2 to 18 times higher than the amount in the parent vitamin alone, depending on the food [ 20 ].

Fortified foods provide most of the vitamin D in American diets [ 1 , 22 ]. For example, almost all of the U.S. milk supply is voluntarily fortified with about 3 mcg/cup (120 IU), usually in the form of vitamin D 3 [ 23 ]. In Canada, milk must be fortified with 0.88–1.0 mcg/100 mL (35–40 IU), and the required amount for margarine is at least 13.25 mcg/100 g (530 IU). Other dairy products made from milk, such as cheese and ice cream, are not usually fortified in the United States or Canada. Plant milk alternatives (such as beverages made from soy, almond, or oats) are often fortified with similar amounts of vitamin D to those in fortified cow's milk (about 3 mcg [120 IU]/cup); the Nutrition Facts label lists the actual amount [ 24 ]. Ready-to-eat breakfast cereals often contain added vitamin D, as do some brands of orange juice, yogurt, margarine, and other food products.

The United States mandates the fortification of infant formula with 1–2.5 mcg/100 kcal (40–100 IU) vitamin D; 1–2 mcg/100 kcal (40–80 IU) is the required amount in Canada [ 1 ].

A variety of foods and their vitamin D levels per serving are listed in Table 3.

* DV = Daily Value. The FDA developed DVs to help consumers compare the nutrient contents of foods and dietary supplements within the context of a total diet. The DV for vitamin D is 20 mcg (800 IU) for adults and children age 4 years and older [ 26 ]. The labels must list vitamin D content in mcg per serving and have the option of also listing the amount in IUs in parentheses. Foods providing 20% or more of the DV are considered to be high sources of a nutrient, but foods providing lower percentages of the DV also contribute to a healthful diet. ** Vitamin D is in the yolk.

Sun exposure

Most people in the world meet at least some of their vitamin D needs through exposure to sunlight [ 1 ]. Type B UV (UVB) radiation with a wavelength of approximately 290–320 nanometers penetrates uncovered skin and converts cutaneous 7-dehydrocholesterol to previtamin D 3 , which in turn becomes vitamin D 3 . Season, time of day, length of day, cloud cover, smog, skin melanin content, and sunscreen are among the factors that affect UV radiation exposure and vitamin D synthesis. Older people and people with dark skin are less able to produce vitamin D from sunlight [ 1 ]. UVB radiation does not penetrate glass, so exposure to sunshine indoors through a window does not produce vitamin D [ 27 ].

The factors that affect UV radiation exposure, individual responsiveness, and uncertainties about the amount of sun exposure needed to maintain adequate vitamin D levels make it difficult to provide guidelines on how much sun exposure is required for sufficient vitamin D synthesis [ 15 , 28 ]. Some expert bodies and vitamin D researchers suggest, for example, that approximately 5–30 minutes of sun exposure, particularly between 10 a.m. and 4 p.m., either daily or at least twice a week to the face, arms, hands, and legs without sunscreen usually leads to sufficient vitamin D synthesis [ 13 , 15 , 28 ]. Moderate use of commercial tanning beds that emit 2% to 6% UVB radiation is also effective [ 13 , 29 ].

However, despite the importance of the sun for vitamin D synthesis, limiting skin exposure to sunlight and UV radiation from tanning beds is prudent [ 28 ]. UV radiation is a carcinogen, and UV exposure is the most preventable cause of skin cancer. Federal agencies and national organizations advise taking photoprotective measures to reduce the risk of skin cancer, including using sunscreen with a sun protection factor (SPF) of 15 or higher, whenever people are exposed to the sun [ 28 , 30 ]. Sunscreens with an SPF of 8 or more appear to block vitamin D-producing UV rays. In practice, however, people usually do not apply sufficient amounts of sunscreen, cover all sun-exposed skin, or reapply sunscreen regularly. Their skin probably synthesizes some vitamin D, even with typically applied sunscreen amounts [ 1 , 28 ].

Dietary supplements

Dietary supplements can contain vitamins D 2 or D 3 . Vitamin D 2 is manufactured using UV irradiation of ergosterol in yeast, and vitamin D 3 is typically produced with irradiation of 7-dehydrocholesterol from lanolin obtained from the wool of sheep [ 13 , 31 ]. An animal-free version of vitamin D3 sourced from lichen is also available [ 32 ]. People who avoid all animal-sourced products can contact dietary supplement manufacturers to ask about their sourcing and processing techniques.

Both vitamins D2 and D3 raise serum 25(OH)D levels, and they seem to have equivalent ability to cure rickets [ 4 ]. In addition, most steps in the metabolism and actions of vitamins D 2 and D 3 are identical. However, most evidence indicates that vitamin D 3 increases serum 25(OH)D levels to a greater extent and maintains these higher levels longer than vitamin D 2 , even though both forms are well absorbed in the gut [ 33-36 ].

Some studies have used dietary supplements containing the 25(OH)D 3 form of vitamin D. Per equivalent microgram dose, 25(OH)D 3 is three to five times as potent as vitamin D 3 [ 37 , 38 ]. However, no 25(OH)D 3 dietary supplements appear to be available to consumers on the U.S. market at this time [ 32 ].

Vitamin D Intakes and Status

Most people in the United States consume less than recommended amounts of vitamin D. An analysis of data from the 2015–2016 National Health and Nutrition Examination Survey (NHANES) found that average daily vitamin D intakes from foods and beverages were 5.1 mcg (204 IU) in men, 4.2 mcg (168 IU) in women, and 4.9 mcg (196 IU) in children age 2–19 years [ 39 ]. In fact, 2013–2016 NHANES data showed that 92% of men, more than 97% of women, and 94% of people age 1 year and older ingested less than the EAR of 10 mcg (400 IU) of vitamin D from food and beverages [ 40 ].

The analysis of 2015–2016 data also showed that 28% of all individuals age 2 years and older in the United States took a dietary supplement containing vitamin D [ 39 ]. In addition, 26% of participants age 2–5 years and 14% of those age 6–11 years took supplements; rates increased with age from 10% of those age 12–19 years to 49% of men and 59% of women age 60 and older. Total vitamin D intakes were three times higher with supplement use than with diet alone; the mean intake from foods and beverages alone for individuals age 2 and older was 4.8 mcg (192 IU) but increased to 19.9 mcg (796 IU) when dietary supplements were included.

Some people take very high doses of vitamin D supplements. In 2013–2014, an estimated 3.2% of the U.S. adult population took supplements containing 100 mcg (4,000 IU) or more vitamin D [ 41 ].

One might expect a large proportion of the U.S. population to have vitamin D inadequacy on the basis of vitamin D intakes from foods, beverages, and even dietary supplements. However, comparing vitamin D intakes to serum 25(OH)D levels is problematic. One reason is that sun exposure affects vitamin D status, so serum 25(OH)D levels are usually higher than would be predicted on the basis of vitamin D dietary intakes alone [ 1 ]. Another reason is that animal foods contain some 25(OH)D. This form of vitamin D is not included in intake surveys and is considerably more potent than vitamins D 2 or D 3 at raising serum 25(OH)D levels [ 42 ].

An analysis of NHANES 2011–2014 data on serum 25(OH)D levels found that most people in the United States age 1 year and older had sufficient vitamin D intakes according to the FNB thresholds [ 43 ]. However, 18% were at risk of inadequacy (levels of 30–49 nmol/L [12–19.6 ng/mL]), and 5% were at risk of deficiency (levels below 30 nmol/L [12 ng/mL]). Four percent had levels higher than 125 nmol/L (50 ng/mL). Proportions at risk of deficiency were lowest among children age 1–5 years (0.5%), peaked at 7.6% in adults age 20–39 years, and fell to 2.9% among adults age 60 years and older; patterns were similar for risks of inadequacy. Rates of deficiency varied by race and ethnicity: 17.5% of non-Hispanic Blacks were at risk of vitamin D deficiency, as were 7.6% of non-Hispanic Asians, 5.9% of Hispanics, and 2.1% of non-Hispanic White people. Again, the pattern was similar for the risk of inadequacy. Vitamin D status in the United States remained stable in the decade between 2003–2004 and 2013–2014.

Vitamin D Deficiency

People can develop vitamin D deficiency when usual intakes are lower over time than recommended levels, exposure to sunlight is limited, the kidneys cannot convert 25(OH)D to its active form, or absorption of vitamin D from the digestive tract is inadequate. Diets low in vitamin D are more common in people who have milk allergy or lactose intolerance and those who consume an ovo-vegetarian or vegan diet [ 1 ].

In children, vitamin D deficiency is manifested as rickets, a disease characterized by a failure of bone tissue to become properly mineralized, resulting in soft bones and skeletal deformities [ 44 ]. In addition to bone deformities and pain, severe rickets can cause failure to thrive, developmental delay, hypocalcemic seizures, tetanic spasms, cardiomyopathy, and dental abnormalities [ 45 , 46 ].

Prolonged exclusive breastfeeding without vitamin D supplementation can cause rickets in infants, and, in the United States, rickets is most common among breastfed Black infants and children [ 47 ]. In one Minnesota county, the incidence rate of rickets in children younger than 3 years in the decade beginning in 2000 was 24.1 per 100,000 [ 48 ]. Rickets occurred mainly in Black children who were breastfed longer, were born with low birthweight, weighed less, and were shorter than other children. The incidence rate of rickets in the infants and children (younger than 7) seen by 2,325 pediatricians throughout Canada was 2.9 per 100,000 in 2002–2004, and almost all patients with rickets had been breastfed [ 49 ].

The fortification of milk (a good source of calcium) and other staples, such as breakfast cereals and margarine, with vitamin D beginning in the 1930s along with the use of cod liver oil made rickets rare in the United States [ 28 , 50 ]. However, the incidence of rickets is increasing globally, even in the United States and Europe, especially among immigrants from African, Middle-Eastern, and Asian countries [ 51 ]. Possible explanations for this increase include genetic differences in vitamin D metabolism, dietary preferences, and behaviors that lead to less sun exposure [ 45 , 46 ].

In adults and adolescents, vitamin D deficiency can lead to osteomalacia, in which existing bone is incompletely or defectively mineralized during the remodeling process, resulting in weak bones [ 46 ]. Signs and symptoms of osteomalacia are similar to those of rickets and include bone deformities and pain, hypocalcemic seizures, tetanic spasms, and dental abnormalities [ 45 ].

Screening for vitamin D status is becoming a more common part of the routine laboratory bloodwork ordered by primary-care physicians, irrespective of any indications for this practice [ 6 , 52-54 ]. No studies have examined whether such screening for vitamin D deficiency results in improved health outcomes [ 55 ]. The U.S. Preventive Services Task Force (USPSTF) found insufficient evidence to assess the benefits and harms of screening for vitamin D deficiency in asymptomatic adults [ 6 ]. It added that no national professional organization recommends population screening for vitamin D deficiency.

Groups at Risk of Vitamin D Inadequacy

Obtaining sufficient vitamin D from natural (nonfortified) food sources alone is difficult. For many people, consuming vitamin D-fortified foods and exposing themselves to some sunlight are essential for maintaining a healthy vitamin D status. However, some groups might need dietary supplements to meet their vitamin D requirements. The following groups are among those most likely to have inadequate vitamin D status.

Breastfed infants

Consumption of human milk alone does not ordinarily enable infants to meet vitamin D requirements, because it provides less than 0.6 to 2.0 mcg/L (25 to 78 IU/L) [ 1 , 56 , 57 ]. The vitamin D content of human milk is related to the mother’s vitamin D status; studies suggest that the breastmilk of mothers who take daily supplements containing at least 50 mcg (2,000 IU) vitamin D 3 have higher levels of the nutrient [ 57 , 58 ].

Although UVB exposure can produce vitamin D in infants, the American Academy of Pediatrics (AAP) advises parents to keep infants younger than 6 months out of direct sunlight, dress them in protective clothing and hats, and apply sunscreen on small areas of exposed skin when sun exposure is unavoidable [ 59 ]. The AAP recommends 10 mcg (400 IU)/day vitamin D supplements for exclusively and partially breastfed infants starting shortly after birth and lasting until they are weaned and consume at least 1,000 mL/day vitamin D-fortified formula or whole milk [ 57 ]. The AAP also recommends 10 mcg (400 IU)/day supplemental vitamin D for all infants who are not breastfed and ingest less than 1,000 mL/day vitamin D-fortified formula or milk. An analysis of NHANES 2009–2016 data found that only 20.5% of breastfed infants and 31.1% of infants who were not breastfed ingested these recommended amounts of supplements [ 60 ].

Older adults

Older adults are at increased risk of developing vitamin D insufficiency, partly because the skin's ability to synthesize vitamin D declines with age [ 1 , 61 ]. In addition, older adults are likely to spend more time than younger people indoors, and they might have inadequate dietary intakes of the vitamin [ 1 ].

People with limited sun exposure

Homebound individuals; people who wear long robes, dresses, or head coverings for religious reasons; and people with occupations that limit sun exposure are among the groups that are unlikely to obtain adequate amounts of vitamin D from sunlight [ 62 ]. The use of sunscreen also limits vitamin D synthesis from sunlight. However, because the extent and frequency of sunscreen use are unknown, the role that sunscreen may play in reducing vitamin D synthesis is unclear [ 1 ].

People with dark skin

Greater amounts of the pigment melanin in the epidermal layer of the skin result in darker skin and reduce the skin’s ability to produce vitamin D from sunlight [ 1 ]. Black Americans, for example, typically have lower serum 25(OH)D levels than White Americans. However, whether these lower levels in persons with dark skin have significant health consequences is not clear [ 14 ]. Those of African American ancestry, for example, have lower rates of bone fracture and osteoporosis than do Whites (see the section below on bone health and osteoporosis).

People with conditions that limit fat absorption

Because vitamin D is fat soluble, its absorption depends on the gut’s ability to absorb dietary fat [ 4 ]. Fat malabsorption is associated with medical conditions that include some forms of liver disease, cystic fibrosis, celiac disease, Crohn’s disease, and ulcerative colitis [ 1 , 63 ]. In addition to having an increased risk of vitamin D deficiency, people with these conditions might not eat certain foods, such as dairy products (many of which are fortified with vitamin D), or eat only small amounts of these foods. Individuals who have difficulty absorbing dietary fat might therefore require vitamin D supplementation [ 63 ].

People with obesity or who have undergone gastric bypass surgery

Individuals with a body mass index (BMI) of 30 or more have lower serum 25(OH)D levels than individuals without obesity. Obesity does not affect the skin’s capacity to synthesize vitamin D. However, greater amounts of subcutaneous fat sequester more of the vitamin [ 1 ]. People with obesity might need greater intakes of vitamin D to achieve 25(OH)D levels similar to those of people with normal weight [ 1 , 64 , 65 ].

Individuals with obesity who have undergone gastric bypass surgery can also become vitamin D deficient. In this procedure, part of the upper small intestine, where vitamin D is absorbed, is bypassed, and vitamin D that is mobilized into the bloodstream from fat stores might not raise 25(OH)D to adequate levels over time [ 66 , 67 ]. Various expert groups—including the American Association of Metabolic and Bariatric Surgery, The Obesity Society, and the British Obesity and Metabolic Surgery Society—have developed guidelines on vitamin D screening, monitoring, and replacement before and after bariatric surgery [ 66 , 68 ]

Vitamin D and Health

The FNB committee that established DRIs for vitamin D found that the evidence was inadequate or too contradictory to conclude that the vitamin had any effect on a long list of potential health outcomes (e.g., on resistance to chronic diseases or functional measures), except for measures related to bone health. Similarly, in a review of data from nearly 250 studies published between 2009 and 2013, the Agency for Healthcare Research and Quality concluded that no relationship could be firmly established between vitamin D and health outcomes other than bone health [ 69 ]. However, because research has been conducted on vitamin D and numerous health outcomes, this section focuses on seven diseases, conditions, and interventions in which vitamin D might be involved: bone health and osteoporosis, cancer, cardiovascular disease (CVD), depression, multiple sclerosis (MS), type 2 diabetes, and weight loss.

Most of the studies described in this section measured serum 25(OH)D levels using various methods that were not standardized by comparing them to the best methods. Use of unstandardized 25(OH)D measures can raise questions about the accuracy of the results and about the validity of conclusions drawn from studies that use such measures and, especially, from meta-analyses that pool data from many studies that use different unstandardized measures [ 5 , 9 , 70 ]. More information about assay standardization is available from the Vitamin D Standardization Program webpage.

Bone health and osteoporosis

Bone is constantly being remodeled. However, as people age—and particularly in women during menopause—bone breakdown rates overtake rates of bone building. Over time, bone density can decline, and osteoporosis can eventually develop [ 71 ].

More than 53 million adults in the United States have or are at risk of developing osteoporosis, which is characterized by low bone mass and structural deterioration of bone tissue that increases bone fragility and the risk of bone fractures [ 72 ]. About 2.3 million osteoporotic fractures occurred in the United States in 2015 [ 73 ]. Osteoporosis is, in part, a long-term effect of calcium and/or vitamin D insufficiency, in contrast to rickets and osteomalacia, which result from vitamin D deficiency. Osteoporosis is most often associated with inadequate calcium intakes, but insufficient vitamin D intakes contribute to osteoporosis by reducing calcium absorption [ 1 ].

Bone health also depends on support from the surrounding muscles to assist with balance and postural sway and thereby reduce the risk of falling. Vitamin D is also needed for the normal development and growth of muscle fibers. In addition, inadequate vitamin D levels can adversely affect muscle strength and lead to muscle weakness and pain (myopathy) [ 1 ].

Most trials of the effects of vitamin D supplements on bone health also included calcium supplements, so isolating the effects of each nutrient is difficult. In addition, studies provided different amounts of nutrients and used different dosing schedules.

Clinical trial evidence on older adults

Among postmenopausal women and older men, many clinical trials have shown that supplements of both vitamin D and calcium result in small increases in bone mineral density throughout the skeleton [ 1 , 74 ]. They also help reduce fracture rates in institutionalized older people. However, the evidence on the impact of vitamin D and calcium supplements on fractures in community-dwelling individuals is inconsistent.

The USPSTF evaluated 11 randomized clinical trials of vitamin D and/or calcium supplementation in a total of 51,419 healthy, community-dwelling adults age 50 years and older who did not have osteoporosis, vitamin D deficiency, or prior fractures [ 75 , 76 ]. It concluded that the current evidence was insufficient to evaluate the benefits and harms of supplementation to prevent fractures. In addition, the USPSTF recommended against supplementation with 10 mcg (400 IU) or less of vitamin D and 1,000 mg or less of calcium to prevent fractures in this population, but it could not determine the balance of benefits and harms from higher doses.

The USPSTF also reviewed the seven published studies on the effects of vitamin D supplementation (two of them also included calcium supplementation) on the risk of falls in community-dwelling adults age 65 years or older who did not have osteoporosis or vitamin D deficiency. It concluded with moderate certainty that vitamin D supplementation does not reduce the numbers of falls or injuries, such as fractures, resulting from falls [ 77 , 78 ]. Another recent systematic review also found that vitamin D and calcium supplements had no beneficial effects on fractures, falls, or bone mineral density [ 79 , 80 ]. In contrast, a meta-analysis of six trials in 49,282 older adults found that daily vitamin D (10 or 20 mcg [400 IU or 800 IU]/day) and calcium (800 or 1,200 mg/day) supplementation for a mean of 5.9 years reduced the risk of any fracture by 6% and of hip fracture by 16% [ 81 ].

One systematic review and meta-analysis of 11 randomized, controlled trials published through 2018 of vitamin D supplementation alone (10–20 mcg [400–800 IU]/day or more at least every week or as rarely as once a year) for 9 months to 5 years found that the supplements provided no protection from fractures in 34,243 older adults [ 81 ].

More recently, a 2022 ancillary study of the Vitamin D and Omega-3 Trial (VITAL; described in the Cancer section below) investigated whether supplemental vitamin D3 (50 mcg [2,000 IU]/day) would lower the risk of fractures in 25,871 generally healthy men age 50 years and older and women age 55 years and older over a median follow-up of 5.3 years [ 82 ]. The mean age of all participants was 67.1 years; 50.6% were women and 20.2% were Black. Most participants were vitamin D sufficient; at baseline, only 2.4% had serum 25(OH)D levels less than 30 nmol/L (12 ng/mL), and 12.9% less than 50 nmol/L (20 ng/mL). Vitamin D supplementation did not lower the risk of total fractures, hip fractures, or nonvertebral fractures as compared with placebo. No substantial between-group differences in fracture incidence were found by race, ethnic group, BMI, age, baseline 25(OH)D levels, or whether participants took supplemental calcium, were at high fracture risk, or had a history of fragility fractures.

Vitamin D supplements for bone health in minority populations

Bone mineral density, bone mass, and fracture risk are correlated with serum 25(OH)D levels in White Americans and Mexican Americans, but not in Black Americans [ 14 , 83 ]. Factors such as adiposity, skin pigmentation, vitamin D binding protein polymorphisms, and genetics contribute to differences in 25(OH)D levels between Black and White Americans.

One clinical trial randomized 260 Black women age 60 years and older (mean age 68.2 years) to receive 60 to 120 mcg (2,400 to 4,800 IU) per day vitamin D 3 supplementation to maintain serum 25(OH)D levels above 75 nmol/L (30 ng/mL) for 3 years [ 84 ]. The results showed no association between 25(OH)D levels or vitamin D dose and the risk of falling in the 184 participants who completed the study. In fact, Black Americans might have a greater risk than White Americans of falls and fractures with daily vitamin D intakes of 50 mcg (2,000 IU) or more [ 14 ]. Furthermore, the bone health of older Black American women does not appear to benefit from raising serum 25(OH)D levels beyond 50 nmol/L (20 ng/mL) [ 84 ].

Vitamin D supplements and muscle function

Studies examining the effects of supplemental vitamin D on muscle strength and on rate of decline in muscle function have had inconsistent results [ 55 ]. One recent clinical trial, for example, randomized 78 frail and near-frail adults age 65 years and older to receive 20 mcg (800 IU) vitamin D 3 , 10 mcg 25(OH)D, or placebo daily for 6 months. The groups showed no significant differences in measures of muscle strength or performance [ 85 ]. Another study randomized 100 community-dwelling men and women age 60 years and older (most were White) with serum 25(OH)D levels of 50 nmol/L (20 ng/ml) or less to 800 IU vitamin D 3 or placebo for 1 year [ 86 ]. Participants in the treatment group whose serum 25(OH)D level was less than 70 nmol/L (28 ng/ml) after 4 months received an additional 800 IU/day vitamin D 3 . Despite increasing serum 25(OH)D levels to an average of more than 80 nmol/L (32 ng/ml), vitamin D supplementation did not affect lower-extremity power, strength, or lean mass.

Conclusions about vitamin D supplements and bone health

All adults should consume recommended amounts of vitamin D and calcium from foods and supplements if needed. Older women and men should consult their health care providers about their needs for both nutrients as part of an overall plan to maintain bone health and to prevent or treat osteoporosis.

Laboratory and animal studies suggest that vitamin D might inhibit carcinogenesis and slow tumor progression by, for example, promoting cell differentiation and inhibiting metastasis. Vitamin D might also have anti-inflammatory, immunomodulatory, proapoptotic, and antiangiogenic effects [ 1 , 87 ]. Observational studies and clinical trials provide mixed evidence on whether vitamin D intakes or serum levels affect cancer incidence, progression, or mortality risk.

Total cancer incidence and mortality

Some observational studies show associations between low serum levels of 25(OH)D and increased risks of cancer incidence and death. In a meta-analysis of 16 prospective cohort studies in a total of 137,567 participants who had 8,345 diagnoses of cancer, 5,755 participants died from cancer [ 88 ]. A 50 nmol/L (20 ng/mL) increase in 25(OH)D levels was associated with an 11% reduction in total cancer incidence rates and, in women but not men, a 24% reduction in cancer mortality rates. A meta-analysis of prospective studies that evaluated the association between serum 25(OH)D levels and cancer incidence (8 studies) or cancer mortality (16 studies) found that cancer risk decreased by 7% and cancer mortality rates decreased by 2% with each 20 nmol/L (8 ng/mL) increase in serum 25(OH)D levels [ 89 ]. Importantly, not all observational studies found higher vitamin D status to be beneficial, and the studies varied considerably in study populations, baseline comorbidities, and measurement of vitamin D levels.

Clinical trial evidence provides some support for the observational findings. For example, three meta-analyses of clinical trial evidence found that vitamin D supplementation does not affect cancer incidence but does significantly reduce total cancer mortality rates by 12%–13% [ 90-92 ]. In the most recent meta-analysis, 10 randomized clinical trials (including the VITAL trial described below) that included 6,537 cancer cases provided 10 to 50 mcg (400 to 2,000 IU) vitamin D 3 daily (six trials) or 500 mcg (20,000 IU)/week to 12,500 mcg (500,000 IU)/year boluses of vitamin D 3 (four trials) [ 91 ]. The study reports included 3–10 years of follow-up data. The vitamin D supplements were associated with serum 25(OH)D levels of 54 to 135 nmol/L (21.6 to 54 ng/mL). Vitamin D supplementation reduced cancer mortality rates by 13%, and most of the benefit occurred with daily supplementation.

The largest clinical trial, VITAL, to investigate the effects of vitamin D supplementation on the primary prevention of cancer in the general population gave 50 mcg (2,000 IU)/day vitamin D 3 supplements with or without 1,000 mg/day marine omega-3 fatty acids or a placebo for a median of 5.3 years [ 93 ]. The study included 25,871 men age 50 years and older and women age 55 years and older who had no history of cancer, and most had adequate serum 25(OH)D levels at baseline. Rates of breast, prostate, and colorectal cancer did not differ significantly between the vitamin D and placebo groups. However, normal-weight participants had greater reductions in cancer incidence and mortality rates than those with overweight or obesity.

A few studies have examined the effect of vitamin D supplementation on specific cancers. Below are brief descriptions of studies of vitamin D and its association with, or effect on, breast, colorectal, lung, pancreatic, and prostate cancers.

Breast cancer

Some observational studies support an inverse association between 25(OH)D levels and breast cancer risk and mortality, but others do not [ 94-97 ]. The Women's Health Initiative clinical trial randomized 36,282 postmenopausal women to receive 400 IU vitamin D 3 plus 1,000 mg calcium daily or a placebo for a mean of 7 years [ 98 ]. The vitamin D 3 and calcium supplements did not reduce breast cancer incidence, and 25(OH)D levels at the start of the study were not associated with breast cancer risk [ 99 ].

In a subsequent investigation for 4.9 years after the study's end, women who had taken the vitamin D and calcium supplements (many of whom continued to take them) had an 18% lower risk of in situ (noninvasive) breast cancer [ 100 ]. However, women with vitamin D intakes higher than 15 mcg (600 IU)/day at the start of the trial and who received the supplements experienced a 28% increased risk of invasive (but not in situ) breast cancer.

Colorectal cancer

A large case-control study included 5,706 individuals who developed colorectal cancer and whose 25(OH)D levels were assessed a median of 5.5 years from blood draw to cancer diagnosis and 7,105 matched controls [ 101 ]. The results showed an association between 25(OH)D levels lower than 30 nmol/L (12 ng/mL) and a 31% higher colorectal cancer risk. Levels of 75 to less than 87.5 nmol/L (30 to less than 35 ng/mL) and 87.5 to less than 100 nmol/L (35 to less than 40 ng/mL) were associated with a 19% and 27% lower risk, respectively. The association was substantially stronger in women.

In the Women's Health Initiative clinical trial (described above), vitamin D 3 and calcium supplements had no effect on rates of colorectal cancer. In a subsequent investigation for 4.9 years after the study's end, women who had taken the vitamin D and calcium supplements (many of whom continued to take them) still had the same colorectal cancer risk as those who received placebo [ 100 ].

Another study included 2,259 healthy individuals age 45 to 75 years who had had one or more serrated polyps (precursor lesions to colorectal cancer) that had been removed [ 102 ]. These participants were randomized to take 25 mcg (1,000 IU) vitamin D 3 , 1,200 mg calcium, both supplements, or a placebo daily for 3–5 years, followed by an additional 3–5 years of observation after participants stopped the treatment. Vitamin D alone did not significantly affect the development of new serrated polyps, but the combination of vitamin D with calcium increased the risk almost fourfold. The VITAL trial found no association between vitamin D supplementation and the risk of colorectal adenomas or serrated polyps [ 103 ].

Lung cancer

A study of cohorts that included 5,313 participants who developed lung cancer and 5,313 matched controls found no association between serum 25(OH)D levels and risk of subsequent lung cancer, even when the investigators analyzed the data by sex, age, race and ethnicity, and smoking status [ 104 ].

Pancreatic cancer

One study comparing 738 men who developed pancreatic cancer to 738 matched controls found no relationship between serum 25(OH)D levels and risk of pancreatic cancer [ 105 ]. Another study that compared 200 male smokers in Finland with pancreatic cancer to 400 matched controls found that participants in the highest quintile of 25(OH)D levels (more than 65.5 nmol/L [26.2 ng/mL]) had a threefold greater risk of developing pancreatic cancer over 16.7 years than those in the lowest quintile (less than 32 nmol/L [12.8 ng/mL]) [ 106 ]. An investigation that pooled data from 10 studies of cancer in 12,205 men and women found that concentrations of 25(OH)D greater than 75 nmol/L (30 ng/mL) but less than 100 nmol/L (40 ng/mL) did not reduce the risk of pancreatic cancer. However, the results did show an increased risk of pancreatic cancer with 25(OH)D levels of 100 nmol/L (40 ng/mL) or above [ 107 ].

Prostate cancer

Research to date provides mixed evidence on whether levels of 25(OH)D are associated with the development of prostate cancer. Several studies published in 2014 suggested that high levels of 25(OH)D might increase the risk of prostate cancer. For example, a meta-analysis of 21 studies that included 11,941 men with prostate cancer and 13,870 controls found a 17% higher risk of prostate cancer for participants with higher levels of 25(OH)D [ 108 ]. What constituted a higher level varied by study but was typically at least 75 nmol/L (30 ng/mL). In a cohort of 4,733 men, of which 1,731 had prostate cancer, those with 25(OH)D levels of 45–70 nmol/L (18–28 ng/mL) had a significantly lower risk of the disease than men with either lower or higher values [ 109 ]. This U-shaped association was most pronounced for men with the most aggressive forms of prostate cancer. A case-control analysis of 1,695 cases of prostate cancer and 1,682 controls found no associations between 25(OH)D levels and prostate cancer risk [ 110 ]. However, higher serum 25(OH)D levels (at a cut point of 75 nmol/L [30 ng/mL]) were linked to a modestly higher risk of slow-growth prostate cancer and a more substantial lower risk of aggressive disease.

Since 2014, however, several published studies and meta-analyses have found no relationship between 25(OH)D levels and prostate cancer risk [ 111 , 112 ]. For example, an analysis was conducted of 19 prospective studies that provided data on prediagnostic levels of 25(OH)D for 13,462 men who developed prostate cancer and 20,261 control participants [ 113 ]. Vitamin D deficiency or insufficiency did not increase the risk of prostate cancer, and higher 25(OH)D concentrations were not associated with a lower risk.

Several studies have examined whether levels of 25(OH)D in men with prostate cancer are associated with a lower risk of death from the disease or from any cause. One study included 1,119 men treated for prostate cancer whose plasma 25(OH)D levels were measured 4.9 to 8.6 years after their diagnosis. Among the 198 participants who died (41 deaths were due to prostate cancer), 25(OH)D levels were not associated with risk of death from prostate cancer or any cause [ 114 ]. However, a meta-analysis of seven cohort studies that included 7,808 men with prostate cancer found higher 25(OH)D levels to be significantly associated with lower mortality rates from prostate cancer or any other cause [ 115 ]. A dose-response analysis found that each 20 nmol/L [8 ng/mL] increase in 25(OH)D was associated with a 9% lower risk of both all-cause and prostate cancer-specific mortality.

For men with prostate cancer, whether vitamin D supplementation lengthens cancer-related survival is not clear. A meta-analysis of three randomized controlled trials in 1,273 men with prostate cancer found no significant differences in total mortality rates between those receiving vitamin D supplementation (from 10 mcg [400 IU]/day for 28 days to 45 mcg [1,800 IU] given in three doses total at 2-week intervals) and those receiving a placebo [ 116 ].

Conclusions about vitamin D and cancer

The USPSTF stated that, due to insufficient evidence, it was unable to assess the balance of benefits and harms of supplemental vitamin D to prevent cancer [ 117 ]. Taken together, studies to date do not indicate that vitamin D with or without calcium supplementation reduces the incidence of cancer, but adequate or higher 25(OH)D levels might reduce cancer mortality rates. Further research is needed to determine whether vitamin D inadequacy increases cancer risk, whether greater exposure to the nutrient can prevent cancer, and whether some individuals could have an increased risk of cancer because of their vitamin D status over time.

Cardiovascular disease

Vitamin D helps regulate the renin-angiotensin-aldosterone system (and thereby blood pressure), vascular cell growth, and inflammatory and fibrotic pathways [ 118 ]. Vitamin D deficiency is associated with vascular dysfunction, arterial stiffening, left ventricular hypertrophy, and hyperlipidemia [ 119 ]. For these reasons, vitamin D has been linked to heart health and risk of CVD.

Observational studies support an association between higher serum 25(OH)D levels and a lower risk of CVD incidence and mortality. For example, a meta-analysis included 34 observational studies that followed 180,667 participants (mean age greater than 50 years) for 1.3 to more than 32 years. The results showed that baseline serum 25(OH)D levels were inversely associated with total number of CVD events (including myocardial infarction, ischemic heart disease, heart failure, and stroke) and mortality risk [ 120 ]. Overall, the risk of CVD events was 10% lower for each 25 nmol/L (10 ng/mL) increase in serum 25(OH)D.

Another large observational study that followed 247,574 adults from Denmark for 0–7 years found that levels of 25(OH)D that were low (about 12.5 nmol/L [5 ng/mL]) and high (about 125 nmol/L [50 ng/mL]) were associated with a greater risk of mortality from CVD, stroke, and acute myocardial infarction [ 121 ]. Other meta-analyses of prospective studies have found associations between lower vitamin D status measured by serum 25(OH)D levels or vitamin D intakes and an increased risk of ischemic stroke, ischemic heart disease, myocardial infarction, and early death [ 122 , 123 ].

In contrast to the observational studies, clinical trials have provided little support for the hypothesis that supplemental vitamin D reduces the risk of CVD or CVD mortality. For example, a 3-year trial in New Zealand randomized 5,110 adults (mean age 65.9 years) to a single dose of 5,000 mcg (200,000 IU) vitamin D 3 followed by 2,500 mcg (100,000 IU) each month or a placebo for a median of 3.3 years [ 124 ]. Vitamin D supplementation had no effect on the incidence rate of myocardial infarction, angina, heart failure, arrhythmia, arteriosclerosis, stroke, venous thrombosis, or death from CVD. Similarly, the VITAL clinical trial described above found that vitamin D supplements did not significantly decrease rates of heart attacks, strokes, coronary revascularization, or deaths from cardiovascular causes [ 93 ]. Moreover, the effects did not vary by baseline serum 25(OH)D levels or whether participants took the trial’s omega-3 supplement in addition to vitamin D.

However, another clinical trial designed to investigate bone fracture risk found that 800 IU/day vitamin D 3 (with or without calcium) or a placebo in 5,292 adults age 70 years and older for a median of 6.2 years offered protection from cardiac failure, but not myocardial infarction or stroke [ 125 ].

High serum cholesterol levels and hypertension are two of the main risk factors for CVD. The data on supplemental vitamin D and cholesterol levels are mixed, as shown in one meta-analysis of 41 clinical trials in a total of 3,434 participants (mean age 55 years). The results of this analysis showed that 0.5 mcg (20 IU) to 214 mcg (8,570 IU)/day vitamin D supplementation (mean of 2,795 IU) for 6 weeks to 3 years reduced serum total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels, but not high-density lipoprotein cholesterol levels [ 126 ].

Studies of the effects of vitamin D supplements on hypertension have also had mixed findings. In one meta-analysis of 46 clinical trials that included 4,541 participants, vitamin D supplements (typically 40 mcg [1,600 IU]/day or less) for a minimum of 4 weeks had no significant effects on systolic or diastolic blood pressure [ 127 ]. In contrast, another meta-analysis of 30 clinical trials in 4,744 participants (mean age 54.5 years) that administered 5 mcg (200 IU) to 300 mcg (12,000 IU)/day vitamin D 3 for a mean of 5.6 months showed that more than 20 mcg (800 IU)/day significantly reduced systolic and diastolic blood pressure in normal-weight participants who had hypertension [ 128 ]. However, more than 20 mcg (800 IU)/day vitamin D 3 , when taken with calcium supplements, significantly increased blood pressure in participants with overweight and obesity. Another meta-analysis of genetic studies in 146,581 participants (primarily adults) found that a low vitamin D status increased blood pressure and hypertension risk in people with genetic variants associated with low endogenous production of 25(OH)D [ 129 ].

Overall, clinical trials show that vitamin D supplementation does not reduce CVD risk, even for people with low 25(OH)D status (below 20 nmol/L [12 ng/mL]) at baseline [ 93 , 124 ].

Vitamin D is involved in various brain processes, and vitamin D receptors are present on neurons and glia in areas of the brain thought to be involved in the pathophysiology of depression [ 130 ].

A systematic review and meta-analysis of 14 observational studies that included a total of 31,424 adults (mean age ranging from 27.5 to 77 years) found an association between deficient or low levels of 25(OH)D and depression [ 130 ].

Clinical trials, however, do not support these findings. For example, a meta-analysis of nine trials with a total of 4,923 adult participants diagnosed with depression or depressive symptoms found no significant reduction in symptoms after supplementation with vitamin D [ 131 ]. The trials administered different amounts of vitamin D (ranging from 10 mcg [400 IU]/day to 1,000 mcg [40,000 IU]/week). They also had different study durations (5 days to 5 years), mean participant ages (range, 22 years to 75 years), and baseline 25(OH)D levels; furthermore, some but not all studies administered concurrent antidepressant medications.

Three trials conducted since that meta-analysis also found no effect of vitamin D supplementation on depressive symptoms. One trial included 206 adults (mean age 52 years) who were randomized to take a bolus dose of 2,500 mcg (100,000 IU) vitamin D 3 followed by 500 mcg (20,000 IU)/week or a placebo for 4 months [ 132 ]. Most participants had minimal or mild depression, had a low mean baseline 25(OH) level of 33.8 nmol/L (13.5 ng/mL), and were not taking antidepressants. The second trial included 155 adults age 60–80 years who had clinically relevant depressive symptoms, no major depressive disorder, and serum 25(OH)D levels less than 50 to 70 nmol/L (20 to 28 ng/mL) depending on the season; in addition, they were not taking antidepressants [ 133 , 134 ]. Participants were randomized to take either 30 mcg (1,200 IU)/day vitamin D 3 or a placebo for 1 year. In the VITAL trial described above, 16,657 men and women 50 years of age and older with no history of depression and 1,696 with an increased risk of recurrent depression (that had not been medically treated for the past 2 years) were randomized to take 50 mcg (2,000 IU)/day vitamin D 3 (with or without fish oil) or a placebo for a median of 5.3 years [ 135 ]. The groups showed no significant differences in the incidence and recurrent rates of depression, clinically relevant depressive symptoms, or changes in mood scores.

Overall, clinical trials did not find that vitamin D supplements helped prevent or treat depressive symptoms or mild depression, especially in middle-age to older adults who were not taking prescription antidepressants. No studies have evaluated whether vitamin D supplements may benefit individuals under medical care for clinical depression who have low or deficient 25(OH)D levels and are taking antidepressant medication.

Multiple sclerosis

MS is an autoimmune disease of the central nervous system that damages the myelin sheath surrounding and protecting nerve cells in the brain and spinal cord. This damage hinders or blocks messages between the brain and body, leading to clinical features, such as vision loss, motor weakness, spasticity, ataxia, tremor, sensory loss, and cognitive impairment [ 136 , 137 ]. Some people with MS eventually lose the ability to write, speak, or walk.

The geographical distribution of MS around the world is unequal. Few people near the equator develop the disease, whereas the prevalence is higher further north and south. This uneven distribution has led to speculation that lower vitamin D levels in people who have less sunlight exposure might predispose them to the disease [ 137 ].

Many epidemiological and genetic studies have shown an association between MS and low 25(OH)D levels before and after the disease begins [ 137 ]. Observational studies suggest that adequate vitamin D levels might reduce the risk of contracting MS and, once MS is present, decrease the risk of relapse and slow the disease's progression [ 138 ]. One study, for example, tested 25(OH)D levels in 1,092 women in Finland an average of 9 years before their MS diagnosis and compared their outcomes with those of 2,123 similar women who did not develop MS [ 139 ]. More than half the women who developed MS had deficient or insufficient vitamin D levels. Women with 25(OH)D levels of less than 30 nmol/L (12 ng/mL) had a 43% higher MS risk than women with levels of 50 nmol/L (20 ng/mL) or higher. Among the women with two or more serum 25(OH)D samples taken before diagnosis (which reduced random measurement variation), a 50 nmol/L increase in 25(OH)D was associated with a 41% reduced risk of MS, and 25(OH)D levels less than 30 nmol/L were associated with an MS risk that was twice as high as levels of 50 nmol/L or higher.

Two earlier prospective studies of similar design—one in the United States with 444 non-Hispanic White individuals [ 140 ] and the other with 576 individuals in northern Sweden [ 141 ]—found that levels of 25(OH)D greater than 99.1 nmol/L (39.6 ng/mL) and at least 75 nmol/L (30 ng/mL), respectively, were associated with a 61%–62% lower risk of MS.

No clinical trials have examined whether vitamin D supplementation can prevent the onset of MS, but several have investigated whether supplemental vitamin D can help manage the disease. A 2018 Cochrane Review analyzed 12 such trials that had a total of 933 participants with MS; the reviewers judged all of these trials to be of low quality [ 137 ]. Overall, vitamin D supplementation, when compared with placebo administration, had no effect on relevant clinical outcomes, such as recurrent relapse or worsened disability.

Experts have reached no firm consensus on whether vitamin D can help prevent MS given the lack of clinical trial evidence [ 142 ]. In addition, studies have not consistently shown that vitamin D supplementation tempers the signs and symptoms of active MS or reduces rates of relapse.

Type 2 diabetes

Vitamin D plays a role in glucose metabolism. It stimulates insulin secretion via the vitamin D receptor on pancreatic beta cells and reduces peripheral insulin resistance through vitamin D receptors in the muscles and liver [ 143 ]. Vitamin D might be involved in the pathophysiology of type 2 diabetes through its effects on glucose metabolism and insulin signaling as well as its ability to reduce inflammation and improve pancreatic beta-cell function [ 1443 , 145 ].

Observational studies have linked lower serum 25(OH)D levels to an increased risk of diabetes, but their results might have been confounded by the fact that many participants were overweight or had obesity and were therefore more predisposed to developing diabetes and having lower 25(OH)D levels [ 1 ]. A review of 71 observational studies in adults with and without type 2 diabetes from 16 countries found a significant inverse relationship between vitamin D status and blood sugar levels in participants who did and did not have diabetes [ 146 ].

In contrast to observational studies, clinical trials provide little support for the benefits of vitamin D supplementation for glucose homeostasis. One trial included 65 adult men and women (mean age 32 years) with overweight or obesity who were otherwise healthy, did not have diabetes, and had low serum vitamin D levels (at or below 50 nmol/L [20 ng/mL]) [ 147 ]. The investigators randomly assigned participants to receive either a bolus oral dose of 2,500 mcg (100,000 IU) vitamin D 3 followed by 100 mcg (4,000 IU)/day or a placebo for 16 weeks. In the 54 participants who completed the study, vitamin D supplementation did not improve insulin sensitivity or insulin secretion in comparison with placebo.

One systematic review and meta-analysis evaluated 35 clinical trials that included 43,407 adults with normal glucose tolerance, prediabetes, or type 2 diabetes who received a median of 83 mcg (3,332 IU)/day vitamin D supplements or placebo for a median of 16 weeks [ 148 ]. Vitamin D had no significant effects on glucose homeostasis, insulin secretion or resistance, or hemoglobin A1c levels (a measure of average blood sugar levels over the previous 2–3 months), irrespective of the study population, vitamin D dose, or trial quality.

Several trials have investigated whether vitamin D supplementation can prevent the transition from prediabetes to diabetes in patients with adequate 25(OH)D levels, and all have had negative results. In a trial in Norway, 511 men and women age 25–80 years (mean age 62 years) with prediabetes received 500 mcg (20,000 IU) vitamin D 3 or a placebo each week for 5 years [ 149 ]. The results showed no significant differences in rates of progression to type 2 diabetes; in serum glucose, insulin, or hemoglobin A1c levels; or in measures of insulin resistance. At baseline, participants had an adequate mean serum 25(OH)D level of 60 nmol/L (24 ng/mL).

The largest trial to date of vitamin D supplements for diabetes prevention randomized 2,423 men and women age 25 years and older (mean age 60 years) with prediabetes and overweight or obesity (mean BMI of 32.1) to 100 mcg (4,000 IU)/day vitamin D 3 or placebo for a median of 2.5 years [ 145 ]. Most participants (78%) had adequate serum levels of vitamin D at baseline (at least 50 nmol/L [20 ng/mL]). Vitamin D did not significantly prevent the development of diabetes in comparison with placebo. However, a post hoc analysis showed a 62% lower incidence of diabetes among participants with low baseline serum 25(OH)D levels (less than 30 nmol/L [12 ng/mL]) who took the vitamin D supplement than among those who took the placebo [ 145 , 150 ].

Studies have also assessed the value of vitamin D supplementation for managing diabetes, and they have found that the vitamin offers limited benefits. One meta-analysis of 20 clinical trials compared the effects of 0.5 mcg (20 IU)/day to 1,250 mcg (50,000 IU)/week vitamin D supplementation for 2–6 months with those of placebo on glycemic control in 2,703 adults from around the world who had diabetes [ 143 ]. The vitamin D reduced insulin resistance to a small but significant degree, especially in people taking more than 50 mcg (2,000 IU)/day who were vitamin D deficient at baseline, had good glycemic control, did not have obesity, and were of Middle Eastern ethnicity. However, the supplementation had no significant effects on fasting blood glucose, hemoglobin A1c, or fasting insulin levels.

Clinical trials to date provide little evidence that vitamin D supplementation helps maintain glucose homeostasis, reduces the risk of progression from prediabetes to type 2 diabetes, or helps manage the disease, particularly in vitamin D-replete individuals.

Weight loss

Observational studies indicate that greater body weights are associated with lower vitamin D status, and individuals with obesity frequently have marginal or deficient circulating 25(OH)D levels [ 151 ]. However, clinical trials do not support a cause-and-effect relationship between vitamin D and weight loss.

A systematic review and meta-analysis of 15 weight-loss intervention studies that used caloric restriction, exercise, or both, but not necessarily vitamin D supplementation or other treatments, found that people who lost weight had significantly greater increases in serum 25(OH)D levels than those who maintained their weight [ 152 ]. In another study, 10 mcg (400 IU)/day vitamin D and 1,000 mg/day calcium supplementation slightly, but significantly, reduced weight gain amounts in comparison with placebo in postmenopausal women, especially those with a baseline total calcium intake of less than 1,200 mg/day [ 153 ]. However, a meta-analysis of 12 vitamin D supplementation trials (including 5 in which body composition measurements were primary outcomes) found that vitamin D supplements without calorie restriction did not affect body weight or fat mass when the results were compared with those of placebo [ 154 ].

Overall, the available research suggests that consuming higher amounts of vitamin D or taking vitamin D supplements does not promote weight loss.

Health Risks from Excessive Vitamin D

Excess amounts of vitamin D are toxic. Because vitamin D increases calcium absorption in the gastrointestinal tract, vitamin D toxicity results in marked hypercalcemia (total calcium greater than 11.1 mg/dL, beyond the normal range of 8.4 to 10.2 mg/dL), hypercalciuria, and high serum 25(OH)D levels (typically greater than 375 nmol/l [150 ng/mL]) [ 155 ]. Hypercalcemia, in turn, can lead to nausea, vomiting, muscle weakness, neuropsychiatric disturbances, pain, loss of appetite, dehydration, polyuria, excessive thirst, and kidney stones.

In extreme cases, vitamin D toxicity causes renal failure, calcification of soft tissues throughout the body (including in coronary vessels and heart valves), cardiac arrhythmias, and even death. Vitamin D toxicity has been caused by consumption of dietary supplements that contained excessive vitamin D amounts because of manufacturing errors, that were taken inappropriately or in excessive amounts, or that were incorrectly prescribed by physicians, [ 155-157 ].

Experts do not believe that excessive sun exposure results in vitamin D toxicity because thermal activation of previtamin D 3 in the skin gives rise to various non-vitamin D forms that limit formation of vitamin D 3 . Some vitamin D 3 is also converted to nonactive forms [ 1 ]. However, frequent use of tanning beds, which provide artificial UV radiation, can lead to 25(OH)D levels well above 375–500 nmol/L (150–200 ng/mL) [ 158-160 ].

The combination of high intakes of calcium (about 2,100 mg/day from food and supplements) with moderate amounts of vitamin D (about 19 mcg [765 IU]/day from food and supplements) increased the risk of kidney stones by 17% over 7 years among 36,282 postmenopausal women who were randomly assigned to take 1,000 mg/day calcium and 10 mcg (400 IU)/day vitamin D or a placebo [ 161 ]. However, other, shorter (from 24 weeks to 5 years) clinical trials of vitamin D supplementation alone or with calcium in adults found greater risks of hypercalcemia and hypercalciuria, but not of kidney stones [ 162 , 163 ].

The FNB established ULs for vitamin D in 2010 (Table 4) [ 1 ]. While acknowledging that signs and symptoms of toxicity are unlikely at daily intakes below 250 mcg (10,000 IU), the FNB noted that even vitamin D intakes lower than the ULs might have adverse health effects over time. The FNB recommended avoiding serum 25(OH)D levels above approximately 125–150 nmol/L (50–60 ng/mL), and it found that even lower serum levels (approximately 75–120 nmol/L [30–48 ng/mL]) are associated with increases in rates of all-cause mortality, risk of cancer at some sites (e.g., pancreas), risk of cardiovascular events, and number of falls and fractures among older adults.

Interactions with Medications

Vitamin D supplements may interact with several types of medications. A few examples are provided below. Individuals taking these and other medications on a regular basis should discuss their vitamin D intakes and status with their health care providers.

The weight-loss drug orlistat (Xenical and alli), together with a reduced-fat diet, can reduce the absorption of vitamin D from food and supplements, leading to lower 25(OH)D levels [ 164-167 ].

Statin medications reduce cholesterol synthesis. Because endogenous vitamin D is derived from cholesterol, statins may also reduce vitamin D synthesis [ 167 ]. In addition, high intakes of vitamin D, especially from supplements, might reduce the potency of atorvastatin (Lipitor), lovastatin (Altoprev and Mevacor), and simvastatin (FloLipid and Zocor), because these statins and vitamin D appear to compete for the same metabolizing enzyme [ 167-170 ].

Corticosteroid medications, such as prednisone (Deltasone, Rayos, and Sterapred), are often prescribed to reduce inflammation. These medications can reduce calcium absorption and impair vitamin D metabolism [ 171-173 ]. In the NHANES 2001–2006 survey, 25(OH)D deficiency (less than 25 nmol/L [10 ng/mL]) was more than twice as common among children and adults who reported oral steroid use (11%) than in nonusers (5%) [ 174 ].

Thiazide diuretics

Thiazide diuretics (e.g., Hygroton, Lozol, and Microzide) decrease urinary calcium excretion. The combination of these diuretics with vitamin D supplements (which increase intestinal calcium absorption) might lead to hypercalcemia, especially among older adults and individuals with compromised renal function or hyperparathyroidism [ 167 , 175 , 176 ].

Vitamin D and Healthful Diets

The federal government's 2020–2025 Dietary Guidelines for Americans notes that "Because foods provide an array of nutrients and other components that have benefits for health, nutritional needs should be met primarily through foods. ... In some cases, fortified foods and dietary supplements are useful when it is not possible otherwise to meet needs for one or more nutrients (e.g., during specific life stages such as pregnancy)."

The Dietary Guidelines for Americans describes a healthy dietary pattern as one that

• Milk, many ready-to-eat cereals, and some brands of yogurt and orange juice are fortified with vitamin D. Cheese naturally contains small amounts of vitamin D. Vitamin D is added to some margarines.
• ​​​​​​​Fatty fish, such as salmon, tuna, and mackerel, are very good sources of vitamin D. Beef liver and egg yolks have small amounts of vitamin D.
• ​​​​​​​Limits foods and beverages higher in added sugars, saturated fat, and sodium.
• Limits alcoholic beverages.
• Stays within your daily calorie needs.
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• Chakhtoura M, Rahme M, Fuleihan E-H. Vitamin D metabolism in bariatric surgery. Endocrinol Metab Clin North Am 2017;46:947-82. [ PubMed abstract ]
• Peterson L, Zeng X, Caufield-Noll CP, Schweitzer MA, Magnuson TH, Steele KE. Vitamin D status and supplementation before and after bariatric surgery: A comprehensive literature review. Surg Obes Relat Dis 2016;12:693-702. [ PubMed abstract ]
• Chakhtoura MT, Nakhoul N, Akl EA, Mantzoros CS, El Hajj Guleihan GA. Guidelines on vitamin D replacement in bariatric surgery? Identification and systematic appraisal. Metabolism 2016;65:586-97. [ PubMed abstract ]
• Newberry SJ, Chung M, Shekelle PG, Booth MS, Liu JL, Maher AR, et al. Vitamin D and calcium: A systematic review of health outcomes (update) . Evidence Report/Technology Assessment No. 217. (Prepared by the Southern California Evidence-based Practice Center under Contract No. 290- 2012-00006-I.) AHRQ Publication No. 14-E004-EF. Rockville, MD: Agency for Healthcare Research and Quality. September 2014.
• Sempos CT, Carter GD, Binkley NC. 25-hydroxyvitamin D assays: Standardization, guidelines, problems, and interpretation. Pages 939-57 in Feldman D, Pike JW, Bouillon R, Giovannucci E, Goltzman D, Hewison M, eds. Vitamin D, Volume 1: Biochemistry, Physiology and Diagnostics, Fourth Edition. Elsevier, 2018.
• Jin, J. Vitamin D and calcium supplements for preventing fractures. JAMA 2018;319:1630. [ PubMed abstract ]
• National Institutes of Health Osteoporosis and Related Bone Diseases National Resource Center. Osteoporosis Overview .
• Chung M, Balk EM, Brendel M, Ip S, Lau J, Lee J, et al. Vitamin D and calcium: A systematic review of health outcomes. Evidence Report/Technology Assessment No. 183 prepared by the Tufts Evidence-based Practice Center under Contract No. 290-2007-10055-I. AHRQ Publication No. 09-E015. Rockville, MD: Agency for Healthcare Research and Quality, 2009.
• U.S. Preventive Services Task Force. Vitamin D, calcium, or combined supplementation for the primary prevention of fractures in community-dwelling adults. US Preventive Services Task Force recommendation statement. JAMA 2018;319:1592-9. [ PubMed abstract ]
• Kahwati LC, Weber RP, Pan H, Gourlay M, LeBlanc E, Coker-Schwimmer M, Viswanathan M. Vitamin D, calcium, or combined supplementation for the primary prevention of fractures in community-dwelling adults: Evidence report and systematic review for the US Preventive Services Task Force. JAMA 2018;319:1600-12. [ PubMed abstract ]
• Guirguis-Blake JM, Michael YL, Perdue LA, Coppola EL, Beil TL. Interventions to prevent falls in older adults: Updated evidence report and systematic review for the US Preventive Services Task Force. JAMA 2018;319:1705-16. [ PubMed abstract ]
• U.S. Preventive Services Task Force. Interventions to prevent falls in community-dwelling older adults. US Preventive Services Task Force recommendation statement. JAMA 2018;319:1696-1704. [ PubMed abstract ]
• Bolland MJ, Grey A, Avenell A. Effects of vitamin D supplementation on musculoskeletal health: A systematic review, meta-analysis, and trial sequential analysis. Lancet Diabetes Endocrinol 2018;6:847-58. [ PubMed abstract ]
• Gallagher JC. Vitamin D and bone density, fractures, and falls: The end of the story? Lancet Diabetes Endocrinol 2018;6:834-5. [ PubMed abstract ]
• Yao P, Bennett D, Mafham M, Lin X, Chen Z, Armitage J, Clarke R. Vitamin D and calcium for the prevention of fracture: A systematic review and meta-analysis. JAMA Network Open 2019;2(12):e1917789. doi: 10.1001/jamanetworkopen.2019.17789.
• LeBoff MS, Chou SH, Ratliff KA, Cook NR, Khurana B, Kim E, et al. Supplemental vitamin D and incident fractures in midlife and older adults. N Eng J Med 2022;387:299-309. [ PubMed abstract ]
• Aloia JF, Talwar SA, Pollack S, Yeh J. A randomized controlled trial of vitamin D3 supplementation in African American women. Arch Intern Med 2005;165:1618-23. [ PubMed abstract ]
• Aloia JF, Rubinova R, Fazzari M, Islam S, Mikhail M, Ragolia L. Vitamin D and falls in older African American women: The PODA randomized clinical trial. J Am Geriatr Soc 2019;67:1043-49. [ PubMed abstract ]
• Vaes AMM, Tieland M, Toussaint N, Nilwik R, Verdijk LB, van Loon LJC, de Groot CPGM. Cholecalciferol or 25-hydroxycholecalciferol supplementation does not affect muscle strength and physical performance in prefrail and frail older adults. J Nutr 2018;148:712-20. [ PubMed abstract ]
• Shea MK, Fielding RA, Dawson-Hughes B. The effect of vitamin D supplementation on lower-extremity power and function in older adults: a randomized controlled trial. Am J Clin Nutr 2019;109:369-79. [ PubMed abstract ]
• Manson JE, Bassuk SS, Buring JE. Vitamin D, calcium, and cancer: Approaching daylight? JAMA 2017;317:1217-8. [ PubMed abstract ]
• Yin L, Ordonez-Mena JM, Chen T, Schottker B, Arndt V, Brenner H. Circulating 25-hydroxyvitamin D serum concentration and total cancer incidence and mortality: A systematic review and meta-analysis. Preventive Medicine 2013;57:753-64. [ PubMed abstract ]
• Han J, Guo X, Yu X, Liu S, Cui X, Zhang B, Liang H. 25-hydroxyvitamin D and total cancer incidence and mortality: A meta-analysis of prospective cohort studies. Nutrients 2019;11,2295; doi:10.3390/nu11102295. [ PubMed abstract ]
• Keum N, Giovannucci E. Vitamin D supplements and cancer incidence and mortality: A meta-analysis. British Journal of Cancer 2014;111:976-80. [ PubMed abstract ]
• Keum N, Lee DH, Greenwood DC, Manson JE, Giovannucci E. Vitamin D supplementation and total cancer incidence and mortality: A meta-analysis of randomized controlled trials. Ann Oncol 2019;30:733-43. [ PubMed abstract ]
• Bjelakovic G, Gluud LL, Nikolova D, Whitfield K, Krstic G, Wetterslev J, Gluud C. Vitamin D supplementation for prevention of cancer in adults. Cochrane Database Syst Rev 2014; 23(6):CD007469. doi: 10.1002/14651858.CD007469.pub2. [ PubMed abstract ]
• Manson JE, Cook NR, Lee I-M, Christen W, Bassuk S, Mora S, et al. Vitamin D supplements and prevention of cancer and cardiovascular disease. N Engl J Med 2019:380:33-44. [ PubMed abstract ]
• McNamara M, Rosenberger KD. The significance of vitamin D status in breast cancer: A state of the science review. J Midwifery Womens Health 2019;64:276-88. [ PubMed abstract ]
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• Skaaby T, Husemoen LLN, Thuesen BH, Pisinger C, Jorgensen T, Roswall N, et al. Prospective population-based study of the association between serum 25-hydroxyvitamin-D levels and the incidence of specific types of cancer. Cancer Epidemiol Biomarkers Prev 2014;23:1220-9. [ PubMed abstract ]
• Yao S, Kwan ML, Ergas IJ, Roh JM, Cheng T-YD, Hong C-C, et al. Association of serum level of vitamin D at diagnosis with breast cancer survival: A case-cohort analysis in the Pathways Study. JAMA Oncol 2017;3:351-7. [ PubMed abstract ]
• Wactawski-Wende J, Kotchen JM, Anderson GL, Assaf AR, Brunner RL, O'Sullivan MJ, et al. Calcium plus vitamin D supplementation and the risk of colorectal cancer. N Engl J Med 2006;354:684-96. [ PubMed abstract ]
• Chlebowski RT, Johnson KC, Kooperberg C, Pettinger M, Wactawski-Wende J, Rohan T, et al. Calcium plus vitamin D supplementation and the risk of breast cancer. J Natl Cancer Inst 2007;100:1581-91. [ PubMed abstract ]
• Cauley JA, Chlebowski RT, Wactawski-Wende J, Robbins JA, Rodabough RJ, Chen Z, et al. Calcium plus vitamin D supplementation and health outcomes five years after active intervention ended: The Women's Health Initiative. J Womens Health 2013:22,915-29. [ PubMed abstract ]
• McCullough ML, Zoltick ES, Weinstein SJ, Fedirko V, Wang M, Cook NR, et al. Circulating vitamin D and colorectal cancer risk: An international pooling project of 17 cohorts. J Natl Cancer Inst 2019;111:158-69. [ PubMed abstract ]
• Crockett SD, Barry EL, Mott LA, Ahnen DJ, Robertson DJ, Anderson JC, et al. Calcium and vitamin D supplementation and increased risk of serrated polyps: Results from a randomised clinical trial. Gut. 2019 Mar;68(3):475-486. [ PubMed abstract ]
• Song M, Lee IM, Manson JE, Buring JE, Dushkes R, Gordon D, et al. No association between vitamin D supplementation and risk of colorectal adenomas or serrated polyps in a randomized trial. Clin Gastroeterol Hepatol 2020; published online ahead of print. [ PubMed abstract ]
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• van Duijnhoven FJB, Jenab M, Hveem K, Siersema PD, Fedirko V, Duell EJ, et al. Circulating concentrations of vitamin D in relation to pancreatic cancer risk in European populations. Int J Cancer 2018;142:1189-201. [ PubMed abstract ]
• Stolzenberg-Solomon RZ, Vieth R, Azad A, Pietinen P, Taylor PR, Virtamo J, et al. A prospective nested case-control study of vitamin D status and pancreatic cancer risk in male smokers. Cancer Res 2006;66:10213-9. [ PubMed abstract ]
• Helzlsouer KJ for the VDPP Steering Committee. Overview of the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers. Am J Epidemiol 2010;172:4-9. [ PubMed abstract ]
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• Kristal AR, Till C, Song X, Tangen CM, Goodman PJ, Neuhauser ML, et al. Plasma vitamin D and prostate cancer risk: Results from the Selenium and Vitamin E Cancer Prevention Trial. Cancer Epidemiol Biomarkers Prev 2014;23:1494-504. [ PubMed abstract ]
• Schenk JM, Till CA, Tangen CM, Goodman PJ, Song X, Torkko KC, et al. Serum 25-hydroxyvitamin D concentrations and risk of prostate cancer: Results from the Prostate Cancer Prevention Trial. Cancer Epidemiol Biomarkers Prev 2014;23:1484-93. [ PubMed abstract ]
• Heath AK, Hodge AM, Ebeling PR, Eyles DW, Kvaskoff D, Buchanan DD, et al. Circulating 25-hydroxyvitamin D concentration and risk of breast, prostate, and colorectal cancers: The Melbourne Collaborative Cohort Study. Cancer Epidemiol Biomarkers Prev 2019;28:900-8. [ PubMed abstract ]
• Jiang X, Dimou NL, Al-Dabhani K, Lewis SJ, Martin RM, Haycock PC, et al. Circulating vitamin D concentrations and risk of breast and prostate cancer: A Mendelian randomization study. International Journal of Epidemiology 2019;48:1416-24. [ PubMed abstract ]
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• Nair-Shalliker V, Bang A, Egger S, Clements M, Gardiner RA, Kricker A, et al. Post-treatment levels of plasma 25- and 1,25-dihydroxy vitamin D and mortality in men with aggressive prostate cancer. Scientific Reports 2020;10:7736. [ PubMed abstract ]
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• Shahvazi S, Soltani S, Ahmadi SM, de Souza RJ, Salehi-Abargouei A. The effect of vitamin D supplementation on prostate cancer: A systematic review and meta-analysis of clinical trials. Horm Metab Res 2019;51:11-21. [ PubMed abstract ]
• Moyer VA. Vitamin, mineral, and multivitamin supplements for the primary prevention of cardiovascular disease and cancer: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 2014;160:558-64. [ PubMed abstract ]
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• Zhang R, Li B, Gao X, Tian R, Pan Y, Jiang Y, et al. Serum 25-hydroxyvitamin D and the risk of cardiovascular disease: Dose-response meta-analysis of prospective studies. Am J Clin Nutr 2017;105:810-9. [ PubMed abstract ]
• Durup D, Jorgensen HL, Christensen J, Tjonnland A, Olsen A, Halkjaer J, et al. A reverse J-shaped association between serum 25-hydroxyvitamin D and cardiovascular disease mortality: The CopD study. J Clin Endorcinol Metab 2015;100:2339-46. [ PubMed abstract ]
• Brondum-Jacobsen P, Benn M, Jensen GB, Nordestgaard BG. 25-hydroxyvitamin D levels and risk of ischemic heart disease, myocardial infarction, and early death: Population-based study and meta-analyses of 18 and 17 studies. Arterioscler Thromb Vasc Biol 2012;32:2794-802. [ PubMed abstract ]
• Zhou R, Wang M, Huang H, Li W, Hu Y, Wu T. Lower vitamin D status is associated with an increased risk of ischemic stroke: A systematic review and meta-analysis. Nutrients 2018; 10, 277;doi:10.3390/nu10030277. [ PubMed abstract ]
• Scragg R, Stewart AW, Waayer D, Lawes CMM, Toop L, Sluyter J, et al. Effect of monthly high-dose vitamin D supplementation on cardiovascular disease in the Vitamin D Assessment Study: A randomized clinical trial. JAMA Cardiol 2017;2:608-16. [ PubMed abstract ]
• Ford JA, MacLennan GS, Avenell A, Bolland M, Grey A, Witham M. Cardiovascular disease and vitamin D supplementation: Trial analysis, systematic review, and meta-analysis. Am J Clin Nutr 2014;100:746-55. [ PubMed abstract ]
• Dibaba DT. Effect of vitamin D supplementation on serum lipid profiles: A systematic review and meta-analysis. Nutr Rev 2019;77:890-902. [ PubMed abstract ]
• Beveridge LA, Struthers AD, Khan F, Jorde R, Scragg R, Macdonald HM, et al. Effect of vitamin D supplementation on blood pressure: A systematic review and meta-analysis incorporating individual patient data. JAMA Intern Med 2015;175:745-54. [ PubMed abstract ]
• Golzarand M, Shab-Bidar S, Koochakpoor G, Speakman JR, Djafarian K. Effect of vitamin D3 supplementation on blood pressure in adults: An updated meta-analysis. Nutr Metab Cardiovasc Dis 2016;26:663-73. [ PubMed abstract ]
• Vimaleswaran KS, Cavadino A, Berry DJ, Jorde R, Dieffenbach AK, Lu C, et al. Association of vitamin D status with arterial blood pressure and hypertension risk: A mendelian randomisation study. Lancet Diabetes-Endocrinol 2014;2:719-29. [ PubMed abstract ]
• Anglin RES, Samaan Z, Walter SD, McDonald SD. Vitamin D deficiency and depression in adults: Systematic review and meta-analysis. The British Journal of Psychiatry 2013;202:100-7. [ PubMed abstract ]
• Gowda U, Mutowo MP, Smith BJ, Wluka AE, Renzaho AMN. Vitamin D supplementation to reduce depression in adults: Meta-analysis of randomized controlled trials. Nutrition 2015;31:421-9. [ PubMed abstract ]
• Jorde R, Kubiak J. No improvement in depressive symptoms by vitamin D supplementation: Results from a randomised controlled trial. Journal of Nutrition Science 2018;7:1-7. [ PubMed abstract ]
• de Koning EJ, Lips P, Penninx BWJH, Elders PJM, Heijboer AC, den Heijer M, et al. Vitamin D supplementation for the prevention of depression and poor physical function in older persons: The D-Vitaal study, a randomized clinical trial. Am J Clin Nutr 2019;110:1119-30. [ PubMed abstract ]
• Jorde R, Grimnes G. Vitamin D: No cure for depression. Am J Clin Nutr 2019;110:1043-4. PMID: 31504098 [ PubMed abstract ]
• Okereke OI, Reynolds III CF, Mischoulon D, Chang G, Vyas CM, Cook NR, et al. Effect of long-term vitamin D3 supplementation vs placebo on risk of depression or clinically relevant depressive symptoms and on change in mood scores: A randomized clinical trial. JAMA 2020;324:471-80. [ PubMed abstract ]
• MedLinePlus. Multiple sclerosis. 2020.
• Jagannath VA, Filippini G, Di Pietrantonj C, Asokan GV, Robak EW, Whamond L, Robinson SA. Vitamin D for the management of multiple sclerosis (review). Cochrane Database of Systematic Reviews 2018, issue 9, Art. No.: CD008422. DOI: 10.1002/14651858.CD008422.pub3. [ PubMed abstract ]
• Sintzel MB, Rametta M, Reder AT. Vitamin D and multiple sclerosis: A comprehensive review. Neurol Ther 2018;7:59-85. [ PubMed abstract ]
• Munger K, Hongell K, Aivo J, Soilu-Hanninen M, Surcel H-M, Ascherio A. 25-hydroxyvitamin D deficiency and risk of MS among women in the Finnish Maternity Cohort. Neurology 2017;89: 1578-83. [ PubMed abstract ]
• Munger KL, Levin LI, Hollis BW, Howard NS, Ascherio A. Serum 25-hydroxyvitamin D levels and risk of multiple sclerosis. JAMA 2006;296:2832-8. [ PubMed abstract ]
• Salzer J, Hallmans G, Nystrom M, Stenlund H. Wadell G, Sundstrom P. Vitamin D as a protective factor in multiple sclerosis. Neurology 2012;79:2140-5. [ PubMed abstract ]
• Marrie RA, Beck CA. Preventing multiple sclerosis: To (take) vitamin D or not to (take) vitamin D? Neurology 2017;89:1538-9. [ PubMed abstract ]
• Li X, Liu Y, Zheng Y, Wang P, Zhang Y. The effect of vitamin D supplementation on glycemic control in type 2 diabetes patients: A systematic review and meta-analysis. Nutrients 2018; 10, 375; doi:10.3390/nu10030375 [ PubMed abstract ]
• Mousa A, Naderpoor N, Teede H, Scragg R, de Courten, B. Vitamin D supplementation for improvement of chronic low-grade inflammation in patients with type 2 diabetes: A systematic review and meta-analysis of randomized controlled trials. Nutr Rev 2018;76:380-94. [ PubMed abstract ]
• Pittas A, Dawson-Hughes B, Sheehan P, Ware JH, Knowler WC, Aroda VR, et al. Vitamin D supplementation and prevention of type 2 diabetes. N Engl J Med 2019;381:520-30. [ PubMed abstract ]
• Rafiq S, Jeppesen PB. Is hypovitaminosis D related to incidence of type 2 diabetes and high fasting glucose level in healthy subjects: A systematic review and meta-analysis of observational studies. Nutrients 2018, 10, 59; doi:10.3390/nu10010059. [ PubMed abstract ]
• Mousa A, Naderpoor N, de Courten MPJ, Teede H, Kellow N, Walker K, et al. Vitamin D supplementation has no effect on insulin sensitivity or secretion in vitamin D-deficient, overweight or obese adults: A randomized placebo-controlled trial. Am J Clin Nutr 2017;105:1372-81. [ PubMed abstract ]
• Seida JC, Mitri J, Colmers IN, Majumdar SR, Davidson MB, Edwards AL, et al. Effect of vitamin D3 supplementation on improving glucose homeostasis and preventing diabetes: A systematic review and meta-analysis. J Clin Endocrinol Metab 2014;99:3551-60. [ PubMed abstract ]
• Jorde R, Sollid ST, Svartberg J, Schirmer H, Joakimsen RM, Njolstad I, et al. Vitamin D 20 000 IU per week for five years does not prevent progression from prediabetes to diabetes. J Clin Endocrinol Metab 2016;101:1647-55. [ PubMed abstract ]
• Pittas A, Dawson-Hughes B, Staten M. The authors reply: Vitamin D supplementation and prevention of type 2 diabetes. N Engl J Med 2019;381:1785-6. [ PubMed abstract ]
• Earthman CP, Beckman LM, Masodkar K, Sibley SD. The link between obesity and low circulating 25-hydroxyvitamin D concentrations: considerations and implications. Int J Obes (Lond) 2012;36:387-96. [ PubMed abstract ]
• Mallard SR, Howe AS, Houghton LA. Vitamin D status and weight loss: A systematic review and meta-analysis of randomized and nonrandomized controlled weight-loss trials. Am J Clin Nutr 2016;104:1151-9. [ PubMed abstract ]
• Caan B, Neuhouser M, Aragaki A, Lewis CB, Jackson R, LeBoff MS, et al. Calcium plus vitamin D supplementation and the risk of postmenopausal weight gain. Arch Intern Med 2007;167:893-902. [ PubMed abstract ]
• Pathak K, Soares MJ, Calton EK, Zhao Y, Hallett J. Vitamin D supplementation and body weight status: A systematic review and meta-analysis of randomized controlled trials. Obes Rev 2014;15:528-37. [ PubMed abstract ]
• Galior K, Grebe S, Singh R. Development of vitamin D toxicity from overcorrection of vitamin D deficiency: A review of case reports. Nutrients 2018, 10, 953. [ PubMed abstract ]
• Auguste BL, Avila-Casado C, Bargman JM. Use of vitamin D drops leading to kidney failure in a 54-year-old man. CMAJ 2019;191:E390-4. [ PubMed abstract ]
• Vogiatzi MG, Jacobson-Dickman E, DeBoer MD. Vitamin D supplementation and risk of toxicity in pediatrics: A review of current literature. J Clin Endocrinol Metab 2014;99:1132-41. [ PubMed abstract ]
• Singh P, Trivedi N. Tanning beds and hypervitaminosis D: A case report. Ann Intern Med 2014;160:810-1. [ PubMed abstract ]
• Laurent MR, Gielen E, Pauwels S, Vanderschueren D, Bouillon R. Hypervitaminosis D associated with tanning bed use: A case report. Ann Intern Med 2017;166:155-6. [ PubMed abstract ]
• Perez-Castrillon JL, Vega G, Abad L, Sanz A, Chaves J, Hernandez G, Duenas A. Effects of atorvastatin on vitamin D levels in patients with acute ischemic heart disease. Am J Cardiol 2007;99:903-5. [ PubMed abstract ]
• Jackson RD, LaCroix AZ, Gass M, Wallace RB, Robbins J, Lewis CE, et al. Calcium plus vitamin D supplementation and the risk of fractures. N Engl J Med 2006;354:669-82. [ PubMed abstract ]
• Malihi Z, Lawes CMM, Wu Z, Huang Y, Waayer D, Toop L, et al. Monthly high-dose vitamin D supplementation does not increase kidney stone risk or serum calcium: Results from a randomized controlled trial. Am J Clin Nutr 2019;109:1578-87. [ PubMed abstract ]
• Malihi Z, Wu Z, Stewart AW, Lawes CMM, Scragg R. Hypercalcemia, hypercalciuria, and kidney stones in long-term studies of vitamin D supplementation: A systematic review and meta-analysis. Am J Clin Nutr 2016;104:1039-51. [ PubMed abstract ]
• Gotfredsen A, Westergren Hendel H, Andersen T. Influence of orlistat on bone turnover and body composition. Int J Obes Relat Metab Disord 2001;25:1154-60. [ PubMed abstract ]
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• McDuffie JR, Calis KA, Booth SL, Uwaifo GI, Yanovski JA. Effects of orlistat on fat-soluble vitamins in obese adolescents. Pharmacotherapy 2002;22:814-22. [ PubMed abstract ]
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• Skversky AL, Kumar J, Abramowitz MK, Kaskel FJ, Melamed ML. Association of glucocorticoid use and low 25-hydroxyvitamin D levels: Results from the National Health and Nutrition Examination Survey (NHANES): 2001-2006. J Clin Endocrinol Metab 2011;96:3838-45. [ PubMed abstract ]
• Drinka PJ, Nolten WE. Hazards of treating osteoporosis and hypertension concurrently with calcium, vitamin D, and distal diuretics. J Am Geriatr Soc 1984;32:405-7. [ PubMed abstract ]
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This fact sheet by the National Institutes of Health (NIH) Office of Dietary Supplements (ODS) provides information that should not take the place of medical advice. We encourage you to talk to your health care providers (doctor, registered dietitian, pharmacist, etc.) about your interest in, questions about, or use of dietary supplements and what may be best for your overall health. Any mention in this publication of a specific product or service, or recommendation from an organization or professional society, does not represent an endorsement by ODS of that product, service, or expert advice.

Updated: September 18, 2023 History of changes to this fact sheet

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When to Take Vitamin D: Morning or Night?

Quick health scoop.

• Vitamin D is a fat-soluble vitamin needed to support strong bones and teeth, muscle health, and immune function . †
• While you make some Vitamin D when your skin is exposed to direct sunlight, most people don’t get enough of it this way.
• Most people are Vitamin D insufficient, meaning not enough Vitamin D is being obtained through sun exposure or dietary sources and may benefit from a Vitamin D supplement.
• Many people wonder when to take Vitamin D, morning or night. The answer depends on a few factors.

Vitamin D is a fat-soluble vitamin critical for things like bone and teeth, supporting healthy muscle, and immune regulation. [1][2][3] While your body is signaled to make some Vitamin D when your skin is exposed to direct sunlight, a number of factors affect how much of this nutrient you actually get this way — like where you live, how much time you spend in the sun, use of sun protection, your age, weight, and skin pigmentation. And if you’re wondering can you get Vitamin D through a window or indoors, the answer is no. †

What foods have Vitamin D ? Not many, but you can find some in certain fish, egg yolks, UV-treated mushrooms, and fortified foods like dairy or non-dairy milk, cereals, and orange juice. Still, not everyone is able to meet their needs through food alone.

Due to the inconsistency of skin production and the limited number of foods that naturally provide Vitamin D, many health professionals recommend a Vitamin D supplement. As Vitamin D insufficiency affects over 50% of the global population . [4] It ’ s best to have your doctor check your blood levels so you can find the correct dose.

There is an abundance of Vitamin D supplements to choose from that are designed to meet daily needs. Even better, these supplements are easy to add to your existing wellness routine, offering flexibility in terms of what time of day works best for you to take one.

Learn More: How Much Vitamin D Do You Really Get From The Sun?

W hat are the Vitamin D Health Benefits?

An important question to ask is, what does Vitamin D do ? Below are some of the ways Vitamin D is used by your body to support its functions and your everyday wellness. [5]

• Helps improve calcium absorption †
• Supports bone, teeth, muscle and immune health †
• Vitamin D3 is the body’s preferred form of Vitamin D †

Not getting enough Vitamin D from sun exposure, food sources, and/or supplementation can lead to insufficiency or deficiency. ▲ [5] On the other hand, getting too much Vitamin D can have adverse health effects. This is more likely to occur with high-dose Vitamin D supplementation for a prolonged period than from sun exposure or food sources.

Being proactive is best. If you ’ re unsure whether you get enough Vitamin D, speak with your healthcare provider, who can check your blood levels and determine the most appropriate next steps.

Learn More: What Is Vitamin D Deficiency? Symptoms, Causes, & Treatment Options

W hen is the Best Time to Take Vitamin D?

If you ’ re wondering when to take Vitamin D, morning or night, it depends on a few factors.  While Vitamin D can be taken at any time of day, taking your supplement at the same time daily may help you develop a consistent habit of taking it. For some people, this means taking it with their breakfast in the morning, after brushing their teeth, or in the evening before bed.

One of the most important factors to keep in mind is that Vitamin D is fat-soluble, which means it is best absorbed when taken alongside a source of dietary fat. [1] Regardless of the time of day you take it, time it around a meal that contains some fat to help you get the most out of it. Some fat-rich foods include nut butter, avocados, flax oil, butter, full-fat dairy or nondairy milk, and olives.

For example, in one 2015 study among 50 older adults, researchers found that Vitamin D blood levels were increased by 32% within 12 hours when the participants took a Vitamin D supplement with a high-fat meal, compared to when it was taken on an empty stomach. [6]

Taking it in the Morning

If you choose to take your Vitamin D supplement in the morning, consider having it alongside your breakfast or taking it after you finish your meal and brush your teeth for the day. This is a good option for people who are best at sticking to a morning routine and might otherwise forget to take their supplements later.

Taking it at Night

Taking Vitamin D at night is another option. Just remember to take it with your dinner, evening snack, or shortly after you’ve eaten. This can work well for people who don ’ t always eat breakfast in the morning but can consistently plan to take their Vitamin D with an evening meal before bed.

So When Should I Take My Supplement?

When considering when to take Vitamin D, morning or night, what matters most is choosing the option that works best for your unique needs and schedule, sticking to it as consistently as you can, and taking Vitamin D with a source of dietary fat. This allows your body to regularly receive the Vitamin D it needs with optimal absorption, which is especially important if you ’ re prioritizing correcting diagnosed low blood levels first.

Learn More: What Helps Vitamin D Absorption?

Start Your Vitamin D Journey With Nature Made

There are two forms of Vitamin D. These include ergocalciferol, or Vitamin D2, and cholecalciferol, or Vitamin D3. Research shows that Vitamin D3 is more bioavailable and better for increasing blood levels of Vitamin D and, therefore, your body ’ s preferred form of the nutrient. [7]

Nature Made supplements are formulated with Vitamin D3. Depending on your individual needs and preferences, you might choose a Vitamin D-only supplement or one that contains a mixture of nutrients, such as Vitamin D with vitamin K2 or glucosamine chondroitin.

Nature Made product dosages range from a standard 1,000-2,000 IU maintenance dose of Vitamin D3 to a high-dose 10,000 IU intended to help support diagnosed Vitamin D deficiency ▲ and used over a short time. † [5]

Regardless of which Nature Made Vitamin D product you choose, you ’ ll receive a high-quality supplement free from artificial flavors, synthetic dyes, and gluten. They are available in softgels, tablets, and gummies, depending on your preferences and dosing needs.

Nature Made gummies have many rave reviews that mention their ease of use and great taste. Furthermore, most Nature Made products bear a USP seal, which means their ingredients, potency, and manufacturing process have been independently tested and verified.

Learn More About Vitamin D:

• Vitamin D Immune System Benefits: How Does It Help?
• What Foods Have Vitamin D?
• What Is The Difference Between Vitamin D And Vitamin D3?
• Can You Take Too Much Vitamin D?

Follow @NatureMadeVitamins on Instagram for new product news, healthy tips, and more.

▲ Approx. 29% of the U.S. adults are Vitamin D deficient (<50 nmol/L) Source: Endocrine Society, NHANES

† These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.

• Chauhan K, Shahrokhi M, Huecker MR. Vitamin D. [Updated 2023 Mar 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK441912/
• Bouillon R, Marcocci C, Carmeliet G, et al.  Endocr Rev . 2019;40(4):1109-1151. doi:10.1210/er.2018-00126
• Ma rtens PJ, Gysemans C, Verstuyf A, Mathieu AC. Vitamin D's Effect on Immune Function. Nutrients . 2020;12(5):1248. Published 2020 Apr 28. doi:10.3390/nu12051248
• van Schoor N, Lips P. Global Overview of Vitamin D Status. Endocrinol Metab Clin North Am. 2017;46(4):845-870. doi:10.1016/j.ecl.2017.07.002
• Vitamin D Fact Sheet for Health Professionals. Office of Dietary Supplements. Updated 12 Aug 2022. Available from: https://ods.od.nih.gov/factsheets/Vitamind-HealthProfessional/
• Dawson-Hughes B, Harris SS, Lichtenstein AH, Dolnikowski G, Palermo NJ, Rasmussen H. Dietary fat increases Vitamin D-3 absorption. J Acad Nutr Diet . 2015;115(2):225-230. doi:10.1016/j.jand.2014.09.014
• Lehmann U, Hirche F, Stangl GI, Hinz K, Westphal S, Dierkes J. J Clin Endocrinol Metab. 2013;98(11):4339-4345. doi:10.1210/jc.2012-4287

Lauren Panoff, MPH, RD

NatureMade Contributor

Kalyn Williams, RDN

Science and Health Educator

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Lauren specializes in plant-based living and vegan and vegetarian diets for all ages. She also enjoys writing about parenting and a wide variety of health, environmental, and nutrition topics. Find her at www.laurenpanoff.com.

Kalyn is a Registered Dietitian-Nutritionist and a Science & Health Educator with the Medical and Scientific Communications team at Pharmavite. Her experience in the field of nutrition prior to joining Pharmavite has included community and public health education, media dietetics, and clinical practice in the areas of disordered eating, diabetes, women’s health, and general wellness. Kalyn received her Bachelor of Science degree in Nutrition and Dietetics from Arizona State University in Phoenix, Arizona, and completed her dietetic supervised practice in Maricopa County, AZ, with an emphasis on public health. Kalyn is certified in Integrative and Functional Nutrition through the Academy of Nutrition and Dietetics, where she is an active member in addition to memberships in Dietitians in Functional Medicine, Women’s Health Dietitians, and the International Federation of Eating Disorder Dietitians.

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Demystification of ‘D’ – Debunking the myths around vitamin D

C hildren's health and nutrition is a potential landmine of misinformation and worries. Here, vitamin D myths and misconceptions are the most prevalent ones. Let us try to debunk prevalent myths, providing evidence-based insights on the role Vitamin D plays in the health and well-being of a child.

The importance of accurate information in child health

Knowledge of vitamin D deficiency and its implications on children has drastically increased over the years. However, it is important that we have accurate information because that forms the bedrock of informed child health decisions. Vitamin D is frequently neglected because of the many myths that surround it. Dispelling these falsehoods is essential for informed decision-making and the overall well-being of our children.

Common misconceptions about vitamin D sources

There is tremendous misinformation and myths surrounding vitamin D sources. One of the biggest myths is that sunlight alone guarantees sufficient vitamin D. Sunlight is not enough to meet the required vitamin D levels. There are many misconceptions surrounding dietary sources as well. It is also important to know there are two forms of vitamin D: D2 and D3. One of them is available from the sunlight, but the other is obtained from food.

Sunlight and vitamin D: Separating facts from fiction

Sunlight acts as a primary source of vitamin D, but the question arises: how much sunlight is enough? Evidence-based insights can guide parents in ensuring their children receive the right exposure for optimal health.

Dietary sources: Dispelling myths and introducing supplementation

While maintaining a balanced diet is undoubtedly essential, it might not suffice for meeting your child’s vitamin D requirements. There are many factors owing to which the body doesn't absorb enough vitamin D from food. Food sources like fish and mushrooms are good sources of Vitamin D, but they can't be consumed in large quantities to meet the nutritional requirements of a child. Therefore, it is important to choose fortified food items.

Vitamin D myths specific to kids

Children face unique challenges when it comes to Vitamin D intake. There are several myths surrounding vitamin D in relation to children's health. One common misconception is that ample sun exposure eliminates the need for vitamin D supplements. While sunlight is a vital source, factors like sunscreen use and limited outdoor time can hinder sufficient synthesis.

Additionally, assuming that all children have similar vitamin D requirements is another fallacy; individual needs vary based on factors like age, diet, and overall health. Some may believe that vitamin D deficiencies are rare in children, but studies suggest otherwise, highlighting the importance of dietary intake and supplementation, especially in regions with limited sunlight.

Dispelling these myths is crucial to ensuring that children receive adequate vitamin D, supporting their bone health, immune system, and overall well-being.

Pediatric perspectives: Navigating unique challenges

Experts play a pivotal role in debunking myths. Pediatric perspectives bring to light the unique challenges in understanding vitamin D, emphasising evidence-based insights crucial for informed parenting.

In the intricate journey of pediatric care, ensuring kids get enough vitamin D unveils unique challenges. Picture a bustling household where little ones dart between play and study, each with their own preferences and quirks. Meeting their vitamin D needs becomes a delicate dance, considering diverse diets and sun exposure habits. It's like crafting a personalised adventure map for each child, acknowledging that what works for one may not for another.

Paediatricians, akin to compasses, guide parents through this intricate navigation, emphasising the importance of tailored solutions. Picture a paediatrician as a seasoned explorer, mapping out the optimal vitamin D route for each child's individual terrain, ensuring they thrive under the sunshine of good health.

Debunking vitamin D myths with scientific rigour

Scientific rigour is our guiding principle as we systematically dismantle prevalent myths. Sunlight may sometimes not get absorbed properly by the skin because of layers of sunscreen. Forget the notion of one-size-fits-all; every child is a universe with distinct vitamin D needs. Therefore, they require a personalised plan. Pediatric experts meticulously study and help you conquer this deficiency. Armed with tailored solutions and by debunking myths with a touch of compassionate exploration, our pediatric experts can ensure that kids gain good health.

Ensuring better child health outcomes through informed decision-making

Separating myths from facts stands as a crucial step in the parenting journey. Informed decisions, as we've explored, pave the way for a healthier, happier future for young ones.

To check whether your child is getting adequate levels of vitamin D or not, check out www.tayyarijeetki.in.

Author: Nmami Agarwal, Celebrity Nutritionist |

Founder- Nmami Life

Disclaimer: This article is produced by the Times Internet Spotlight team for Spotlight Brand Studio.

https://www.everydayhealth.com/vitamin-d/vitamin-d-myths-and-facts/

https://www.yalemedicine.org/news/vitamin-d-myths-debunked

https://raisingchildren.net.au/teens/healthy-lifestyle/nutrients/vitamin-d

For more news like this visit TOI . Get all the Latest News , City News , India News , Business News , and Sports News . For Entertainment News , TV News , and Lifestyle Tips visit Etimes

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Are we more concerned about getting sunburned or with our Vitamin D status? I want to take another look at Vitamin D and our epidemic of Vitamin D deficiency.

Vitamin D is a fat-soluble steroid that is used throughout the body for many processes. Some things are commonly known while other may be new ideas. We take it to help balance calcium that is taken from and stored in the bones. Immune function relies on Vitamin D to keep infection at bay. It is also important in the role of mood, autoimmune disease, obesity and likely most chronic disease. It is also widely used in brain development.

Vitamin D’s last step is an endocrine transfer in the kidney that then goes to over 200 tissues throughout the body that have the Vitamin D Receptor (VDR). So with this mind, we can consider why so many have people have Vitamin D deficiency. Sometimes it is that they are not getting the intake of Vitamin D but what if they are and are just not able to utilize it. Likely about half or the patients with the MTHFR mutation or methylation defect also have a defect in their VDR affecting their body’s ability to suppress the production. Cytochrome P (CYP) in the liver can also activate VDR and deactivate the vitamin D molecule. As you can see there are several challenges to ensuring that Vitamin D is present and accounted for in our simplified version of the biochemistry here alone. Sometimes deficiency can be caused by disease.

However, the deficiency has become a new problem and only since doctors have been telling parents to keep their kids out of the sun. We smother our kids with sunscreen so they get very little absorption of the sun. This is not a suggestion that we should allow our kids to get sunburned on a long outing in the sun. There is a balance of ensuring that little bodies and their skin learn how to tolerate the sun from an early age in regular doses and therefore less likely to burn as they get older. Save the safe versions of sunscreen for the hours of 11-3, the middle of the day, when you must be in direct sunlight. But really, this isn’t a pertinent part of the Vitamin D deficiency discussion. We can get plenty of daily levels of Vitamin D before we are even close to the sunburn level. It is estimated that you can get a daily dose of Vitamin D in half the time it takes to burn which can range from 15 minutes for those with fair skin or 2 hours for darker skin. Even individuals with a history of skin cancer can increase their anti-oxidant levels in their skin and tolerate moderate sun without increasing their risk factor for skin cancer reoccurrences. Often chemical ingredients in poorly formulated sunscreens can increase risk factors of skin cancer, as can blocking only UV waves. Look for natural ingredients and blocks for UVA and UVB.

The founder for the Vitamin D Council has observed that three epidemics have started since our society has been taught to shelter kids from the sun: asthma, autism, and autoimmune conditions. These are three very concerning conditions on which parents spend many resources in order to survive the complication of the condition. Kids with asthma respond very quickly to natural treatment and often go off inhalers and steroids within the 1 st month’s visit to me. Autism is more common in households of higher socioeconomical status and a higher educated mom is more likely to listen to medical persuasion to keep her kids out of the sun. Avoiding the sun really is a new idea for the human race, as is sunscreen.

In countries with normal exposure to the sun, natural vitamin D levels are 46 ng/ml. Preference of blood levels depends on risk factors and present illness, sometimes double is preferred and for other patients, it is lower. In general, this is a good number for the already healthy to strive for. Some studies show that Vitamin D can be washed off the skin within 12 hours with any bathing. Sunbathing is the preferred method of getting Vitamin D; however, you can also get it from supplements and some limited food sources like reindeer meat, seagull eggs, lard, cold water fish, sun dried mushrooms, grass-fed meat, eggs, and milk.

Antibiotics and sun exposure is another concern that I want to address. There are several medications, not just antibiotics, that can cause sun sensitivity and your doctor will warm you to stay out of the sun for 48 hours after taking them. It is wise to avoid the sun when you have no other choice but to take these particular pharmaceuticals.

Have questions about vitamin deficiencies? Call Journey of Health today to find balance.

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Insights From The Ultimate Nutrition Bible Run to the Top Podcast | The Ultimate Guide to Running

Wade Lightheart from BiOptimizers joins the show to talk about his new book, “The Ultimate Nutrition Bible”.   We get into the 5 goals - your final weight loss journey, your lean muscle journey, achieving athletic dominance, maximizing your brain power, and maximizing your biospan before diving more deeply into the weight loss and dietary components.  Specifically in those spheres, we talk about key components like clearing emotional blocks, how to eliminate food toxins, how to choose the diet for your genetics, and how metabolic data shapes destinies. Connect, Comment, Community Follow RunnersConnect on Instagram Join the Elite Treatment where you get first dibs on everything RTTT each month! Runners Connect Winner's Circle Facebook Community  RunnersConnect Facebook page GET EXPERT COACHING AT RUNNERSCONNECT! Ultimate Nutrition Bible This week’s show brought to you by: AG 1 Ask yourself - do you get enough green veggies each day? I'll admit, I don't. It's tough to fit all of those greens in with an active and busy lifestyle. But getting in your fruits + veggies is SO crucial as a distance runner for recovery, digestion, and optimal performance. That's where Athletic Greens is a gamechanger. One scoop has 75 bioavailable vitamins, minerals, and whole food-sourced ingredients including a multivitamin, multimineral, probiotic, green superfood blend, and more. That means fewer stomach issues, more focus and energy throughout the day (because the workday matters just as much as the morning run), and overall ... just feeling healthier. Look, if you're struggling to get those fruits + veggies in - or if you keep buying them but they always go bad in the fridge - Athletic Greens will make getting those micronutrients simple and delicious. Get 5 BONUS travel packs and a year's supply of Vitamin D when you order at drinkag1.com/RTTT. Get yours now! TIMELINE Improving your mitochondria is one of the easiest ways to upgrade your performance and make your body work better.  Time-line Nutrition's Mitopure is backed by over a decade of research and is clinically proven to revitalize mitochondria.  Mitopure restores mitochondrial function, so every cell in your body has the energy to do its job and keep you healthy and functioning right. In fact, clinical studies have shown that 500mg of Urolithin, one of the main ingredients in Mitopure, can significantly increase muscle strength & endurance with no other change in lifestyle. Improving your mitochondria is one of the best things you can do for your health and with Mitopure from time-line nutrition, it has never been easier.  Go to timelinenutrition.com and use promo code RUNNERSCONNECT for 10% off the plan of your choice.

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A growing body of research shows that when it comes to bone health, ensuring optimal intake of vitamin K is a critical piece of the puzzle. New research is focusing on the synergistic relationship between vitamin K (specifically, vitamin K2) and vitamin D3, especially in terms of bone strength and cardiovascular health. A group of naturally occurring and structurally similar, fat-soluble vitamins, vitamin K is essential for the proper utilization of calcium. Through its activation of the protein osteocalcin, vitamin K helps to bind newly absorbed calcium to the mineral matrix in bone. In addition, vitamin K has been found to help maintain bone mineral density by decreasing the activity of osteoclasts, a cell that breaks down the bone matrix. Therefore, vitamin K and vitamin D not only share similar qualities but they also act in synergy within the body. Liquid Vitamin D3 with K2 includes 10 mcg of vitamin K2 (as MK-7) and 1,000 IU of vitamin D3 per serving. The tasteless liquid formula can easily be combined with any beverage.

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