The Health Benefits of Vitamin D

Mood and bone booster

vitamin D from the sun

Jordan Siemens / Digital Vision / Getty Images

Vitamin D is a fat-soluble vitamin that is necessary for promoting calcium and phosphorus absorption to build and repair bones. Vitamin D also helps reduce inflammation, aids in the process of cell growth, and plays a role in immune function. While vitamin D is naturally present in some foods, exposure to sunlight is an excellent way to get vitamin D.

18% of Americans are at risk for inadequate vitamin D levels and 5% of Americans are at risk for deficiency. Deficiencies are common in certain population groups and those with less access to sunlight during some parts of the year. Because of this, ensuring adequate vitamin D levels and possible supplementation is important to consider.

Health Benefits

Vitamin D has several vital functions in the body. Getting enough vitamin D is imperative for normal growth and development of bone. In addition to its primary function, vitamin D plays a role in the health of many other systems to prevent disease.

Heart Health

Evidence shows a link between vitamin D status and heart health. Research suggests that low vitamin D status is associated with an increased risk of cardiovascular disease, hypertension, coronary artery disease, heart failure, stroke, and type 2 diabetes.

While there is not sufficient proof for benefit of supplementation, there is evidence to show the importance of vitamin D status in heart health.


Research demonstrates an association between vitamin D supplementation and decreased cancer deaths. In one study, those who supplemented with vitamin D had reduced cancer mortality by 15%. In addition, evidence shows significantly lower mortality for those individuals who supplemented with vitamin D3 compared to vitamin D2.

Immune Health

Vitamin D plays a major role in the immune system. Research shows that those with vitamin D deficiency are at increased risk for infections as well as autoimmune diseases such as type 1 diabetes, rheumatoid arthritis, and inflammatory bowel disease.

Additionally, there are links between adequate vitamin D status and a reduced risk of respiratory infections.


There is significant research showing the feel-good effects of vitamin D for improving mood and decreasing depression.

In a study with 7,534 individuals, vitamin D supplementation showed improvement in symptoms in those with major depressive disorders. This study also supports the potential benefit of vitamin D supplementation for those with negative emotions and anxiety, but more research is needed.

In addition to the potential health benefits listed above, some people take vitamin D to supplement treatment in a wide range of conditions, including:

  • Dental cavities and gum disease prevention
  • Fatigue
  • Fibromyalgia
  • Multiple sclerosis (MS)
  • Pain (such as back painknee pain, and neuropathy)
  • Skin conditions including psoriasis, acne, and eczema
  • Thyroid and kidney disease

There is insufficient evidence to know for sure if vitamin D plays a role in the treatment of these conditions. Always speak with a healthcare professional if you are considering adding a supplement to your regimen.

Possible Side Effects

Vitamin D toxicity is possible if you take too much in supplement form. Vitamin D toxicity causes increased blood calcium levels which can cause symptoms such as nausea, vomiting, abdominal pain, dehydration, confusion, and increased thirst.

Note that toxicity is rare for those who choose sun exposure as their main way of getting vitamin D because the body regulates the amount of vitamin D produced.

Dosage and Preparation

In the United States, the National Institutes of Health's recommendations for vitamin D intake are as follows:

  • Birth to 1 year: 400 IU/day (10 mcg)
  • Between 1 and 70 years: 600 IU/day (15 mcg)
  • Over 70 years: 800 IU/day (20 mcg)
  • Pregnant and nursing people: 600 IU/day (15 mcg)

To maximize the effect of calcium on bone and muscle metabolism, serum vitamin D levels should be between 50 and 75nmol/L.

Routine vitamin D deficiency screening in asymptomatic, non-pregnant adults is not a common practice and is not recommended by a national professional organization at this time. Speak with a health care professional if you think you have symptoms of vitamin D deficiency that warrant a test.

What to Look For

Vitamin D is not found naturally in many foods and if you have limited sun exposure, you may want to consider a vitamin D supplement. Before deciding on a supplement, it is a good idea to have your levels checked by a healthcare professional so you know if your vitamin D status is deficient or sufficient. Based on your level, your healthcare provider can determine the appropriate dose for your needs.

You can find a supplement in pill, chewable, liquids, or gummy form. Chewables, liquids, or gummies may contain added sugar. Make sure to look for a supplement that contains D2 or D3. Both forms are effective, but vitamin D3 increases levels higher for longer. Additionally, look for a supplement with a third-party certification such as NSF International, ConsumerLab, or U.S. Pharmacopeia.

Sources of Vitamin D

Vitamin D is found naturally in some foods, while other foods are fortified with vitamin D.

Naturally vitamin D rich foods: salmon, sardines, canned tuna, cod liver oil, egg yolks, shrimp, mushrooms

Fortified vitamin D foods: milk, certain cereals, yogurt, orange juice

Other Questions

Is there more than one kind of vitamin D?

There are two types of vitamin D: D2 and D3.

  • Vitamin D2 is found in plant foods such as mushrooms and fortified products.
  • Vitamin D3 is found in animal foods such as oily fish, egg yolks, and liver. Vitamin D3 is the form that is produced when your skin is exposed to the sun. Vitamin D3 is more effective at raising the levels in your blood.

What are some risk factors for vitamin D deficiency?

There are certain groups of people who are at higher risk for vitamin D deficiency. They include:

  • People with limited sun exposure. The amount of vitamin D formed through skin exposure varies based on season and location. If you live somewhere with cold fall and winter months, you may have limited sun exposure. Additionally, people who spend little to no time out of doors are likely not receiving enough vitamin D.
  • People who use sunscreen. While wearing sunscreen has many important benefits, it can limit vitamin D production in exposed skin.
  • People with darker skin. Those with darker skin have more melanin, which absorbs the sun's rays and reduces the body's ability to produce vitamin D. Those with darker skin should ensure they consume adequate levels of vitamin D.
  • Older people. As we age, the ability to produce vitamin D decreases. Older people also tend to spend more time indoors with decreased sun exposure.
  • People who can't properly absorb fat (fat malabsorption). Since vitamin D is fat-soluble, it requires some fat to be absorbed efficiently. Those with conditions that cause fat malabsorption such as cystic fibrosis, Crohn's disease, and chronic liver disease may be at increased risk for vitamin D deficiency.
  • Families that use breastmilk. There is deficient vitamin D in breastmilk alone. Consult a pediatrician before supplementing vitamin D in infants.
9 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Institutes of Health Office of Dietary Supplements. Vitamin D Fact Sheet for Health Professionals.

  2. Saponaro F, Marcocci C, Zucchi R. Vitamin D status and cardiovascular outcomeJ Endocrinol Invest. 2019;42(11):1285-1290. doi:10.1007/s40618-019-01057-y

  3. Zhang Y, Fang F, Tang J, et al. Association between vitamin D supplementation and mortality: systematic review and meta-analysis BMJ. 2019;366:l4673. Published 2019 Aug 12. doi: /10.1136/bmj.l4673

  4. Martens PJ, Gysemans C, Verstuyf A, Mathieu AC. Vitamin D's Effect on Immune FunctionNutrients. 2020;12(5):1248. doi: 10.3390/nu12051248

  5. Grant WB, Lahore H, McDonnell SL, et al. Evidence that Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections and DeathsNutrients. 2020;12(4):988. doi: 10.3390/nu12040988

  6. Cheng YC, Huang YC, Huang WL. The effect of vitamin D supplement on negative emotions: A systematic review and meta-analysisDepress Anxiety. 2020;37(6):549-564.

  7. Marcinowska-Suchowierska E, Kupisz-Urbańska M, Łukaszkiewicz J, Płudowski P, Jones G. Vitamin D Toxicity-A Clinical Perspective. Front Endocrinol (Lausanne). 2018;9:550. doi: 10.3389/fendo.2018.00550

  8. National Institutes of Health Office of Dietary Supplements. Vitamin D Fact Sheet for Health Professionals.

  9. Taksler GB, Cutler DM, Giovannucci E, Keating NL. Vitamin D deficiency in minority populations. Public Health Nutr. 2015;18(3):379-391. doi:10.1017/S1368980014000457

Additional Reading
  • Carrillo AE1, Flynn MG, Pinkston C, Markofski MM, Jiang Y, Donkin SS, Teegarden D. Impact of Vitamin D Supplementation During a Resistance Training Intervention on Body Composition, Muscle Function, and Glucose Tolerance in Overweight and Obese Adults. Clin Nutr. 2013 Jun;32(3):375-81. doi: 10.1016/j.clnu.2012.08.014.

  • Urashima M, Segawa T, Okazaki M, Kurihara M, Wada Y, Ida H. Randomized Trial of Vitamin D Supplementation to Prevent Seasonal Influenza A in Schoolchildren. Am J Clin Nutr. 2010 91:1255-60.

  • Cannell JJ, Vieth R, Umhau JC, et al. Epidemic Influenza and Vitamin D. Epidemiol Infect. 2006; 134:1129-40.
  • Ginde AA, Mansbach JM, Camargo CA, Jr. Association Between Serum 25-Hydroxyvitamin D Level and Upper Respiratory Tract Infection in the Third National Health and Nutrition Examination Survey. Arch Intern Med. 2009; 169:384-90.
  • Giovannucci E, Liu Y, Hollis BW, Rimm EB. 25-hydroxyvitamin D and Risk of Myocardial Infarction in Men: a Prospective Study. Arch Intern Med. 2008; 168:1174-80.
  • Gorham ED, Garland CF, Garland FC, Grant WB, Mohr SB, Lipkin M, Newmark HL, Giovannucci E, Wei M, Holick MF. Optimal Vitamin D Status for Colorectal Cancer Prevention: a Quantitative Meta-analysis. Am J Prev Med. 2007 Mar;32(3):210-6.
  • Heaney, Robert P. “The Vitamin D Requirement in Health and Disease.” The Journal of Steroid Biochemistry & Molecular Biology 97 (2005):13-9.
  • Holick MF. Vitamin D. In: Shils M, Olson J, Shike M, Ross AC, ed. Modern Nutrition in Health and Disease, 9th ed. Baltimore: Williams and Wilkins, 1999. 
  • National Institutes of Health Office of Dietary Supplements. Vitamin D: Dietary Supplement Fact Sheet. University of Ottawa Evidence-based Practice Center. Effectiveness and Safety of Vitamin D in Relation to Bone Health. Agency for Healthcare Research and Quality. Aug 2007: 07-E013.
  • Salehpour A1, Hosseinpanah F, Shidfar F, Vafa M, Razaghi M, Dehghani S, Hoshiarrad A, Gohari M. A 12-week Double-blind Randomized Clinical Trial of Vitamin D₃ Supplementation on Body Fat Mass in Healthy Overweight and Obese Women. Nutr J. 2012 Sep 22;11:78. doi: 10.1186/1475-2891-11-78.
  • Wilkins, Consuelo H. and Yvette I. Sheline, et al. “Vitamin D Deficiency Is Associated with Low Mood and Worse Cognitive Performance in Older Adults.” American Journal of Geriatric Psychiatry 14 (2006): 1032-40.

By Rebecca Jaspan, MPH, RD, CDN, CDCES
Rebecca Jaspan is a registered dietitian specializing in anorexia, binge eating disorder, and bulimia, as well as disordered eating and orthorexia.