Over 40 percent of all adults in the United States lacked adequate vitamin D in 2006, according to the National Health and Nutrition Examination Survey 6. In 2010, the Institute of Medicine increased its recommended dietary allowances for vitamin D from 400 to 600 international units per day for most adults and 800 international units per day for people over 70. The best way to increase the level of vitamin D in your body is through exposure to the sun, but you can also get vitamin D from certain foods or supplements.
Soaking Up the Sunlight
Vitamin D exists in two forms: ergocalciferol, or D-2, and cholecalciferol, or D-3. Your skin produces vitamin D-3 when exposed to ultraviolet B radiation from the sun. Exposure of your arms, legs or back for five to 30 minutes between 10 a.m. and 3 p.m. twice a week is recommended to achieve adequate levels. Darker skin, advanced age and sunscreen use reduce your skin’s ability to synthesize vitamin D. Additionally, latitude, season and time of day greatly affect the amount of vitamin D your skin can produce from exposure to the sun. In most of the United States, very little vitamin D is synthesized in the skin during the winter months.
- Vitamin D exists in two forms: ergocalciferol, or D-2, and cholecalciferol, or D-3.
- Darker skin, advanced age and sunscreen use reduce your skin’s ability to synthesize vitamin D. Additionally, latitude, season and time of day greatly affect the amount of vitamin D your skin can produce from exposure to the sun.
Foods Naturally High in Vitamin D
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Vitamin D, in the form of both D-2 and D-3, is found naturally in some foods. Cod liver oil is an excellent source, providing 1,360 international units of vitamin D in 1 tablespoon. Mushrooms, including maitake and portobella, are a good sources of vitamin D, especially when they have been exposed to ultraviolet light. Egg yolks and cheese also provide small amounts of the vitamin.
- Vitamin D, in the form of both D-2 and D-3, is found naturally in some foods.
- Cod liver oil is an excellent source, providing 1,360 international units of vitamin D in 1 tablespoon.
Foods Fortified with Vitamin D
When a food is fortified, vitamins or minerals that weren’t originally in the food are added to it to make it more nutritious. Because so few foods naturally contain vitamin D, many are fortified to help consumers get more of this essential vitamin. Check nutrition labels to determine whether the foods you eat are fortified and how much vitamin D they provide.
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Vitamin D is available as a dietary supplement in the form of vitamins D-2 and D-3. While these two forms are generally regarded as equivalent, evidence suggests that at high doses vitamin D-2 may be less potent than D-3. If you are vitamin D-deficient, your health care provider may recommend exceeding the recommended dietary allowance until your blood levels return to normal. Do not exceed the upper level intake of 4,000 international units per day for individuals over 9 years of age unless directed to do so by your doctor.
- Vitamin D is available as a dietary supplement in the form of vitamins D-2 and D-3.
- While these two forms are generally regarded as equivalent, evidence suggests that at high doses vitamin D-2 may be less potent than D-3.
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- National Academy of Sciences: Institute of Medicine: Dietary Reference Intakes for Calcium and Vitamin D: Report Brief
- New England Journal of Medicine: Vitamin D Deficiency
- Journal of Clinical Endocrinology and Metabolism: Evaluation, Treatment, and Prevention of Vitamin D Deficiency: an Endocrine Society Clinical Practice Guideline
- USDA: National Nutrient Database for Standard Reference
- National Institutes of Health: Vitamin D: Fact Sheet for Health Professionals
- Nutrition Research: Prevalence and Correlates of Vitamin D Deficiency in US Adults
- Holick MF, Gordon CM. Patient Guide to Vitamin D Deficiency. The Journal of Clinical Endocrinology & Metabolism. 2011;96(7):1-2. doi:10.1210/jcem.96.7.zeg33a
- Sunyecz JA. The use of calcium and vitamin D in the management of osteoporosis. Ther Clin Risk Manag. 2008;4(4):827-836. doi:10.2147/tcrm.s3552
- 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(11):1174-1180. doi:10.1001/archinte.168.11.1174
- Gorham ED, Garland CF, Garland FC, et al. Optimal vitamin D status for colorectal cancer prevention: a quantitative meta analysis. Am J Prev Med. 2007;32(3):210-216. doi:10.1016/j.amepre.2006.11.004
- Lappe JM, Travers-Gustafson D, Davies KM, Recker RR, Heaney RP. Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial. The American Journal of Clinical Nutrition. 2007;85(6):1586-1591. doi:10.1093/ajcn/85.6.1586
- Prentice RL, Pettinger MB, Jackson RD, et al. Health risks and benefits from calcium and vitamin D supplementation: Women’s Health Initiative clinical trial and cohort study. Osteoporos Int. 2013;24(2):567-580. doi:10.1007/s00198-012-2224-2
- 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(5):1255-1260. doi:10.3945/ajcn.2009.29094
- Salehpour A, Hosseinpanah F, Shidfar F, et al. 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;11:78. doi:10.1186/1475-2891-11-78
- Carrillo AE, Flynn MG, Pinkston C, et al. 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;32(3):375-381. doi:10.1016/j.clnu.2012.08.014
- Marcinowska-Suchowierska E, Kupisz-Urbańska M, Łukaszkiewicz J, Płudowski P, Jones G. Vitamin D Toxicity-A Clinical Perspective. Front Endocrinol. 2018;9:550. doi:10.3389/fendo.2018.00550
- Ross AC, Manson JE, Abrams SA, et al. The 2011 report on dietary reference intakes for calcium and vitamin D from the Institute of Medicine: what clinicians need to know. J Clin Endocrinol Metab. 2011;96(1):53-58. doi:10.1210/jc.2010-2704
- Bouillon R, Van Schoor NM, Gielen E, et al. Optimal vitamin D status: a critical analysis on the basis of evidence-based medicine. J Clin Endocrinol Metab. 2013;98(8):E1283-E1304. doi:10.1210/jc.2013-1195
- American Academy of Dermatology. Position Statement of Vitamin D. 2010.
- 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
- Holick MF, Binkley NC, Bischoff-Ferrari HA, et al. Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011;96(7):1911-1930. doi:10.1210/jc.2011-0385
- Cannell JJ, Vieth R, Umhau JC, et al. Epidemic Influenza and Vitamin D. Epidemiol Infect. 2006; 134:1129-40.
- 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. Epub 2012 Aug 31.
- 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.
- 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. Epub 2010 Mar 10.
- 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.
Based in Minneapolis, Minn., Alyssa Northrop is a Registered Dietitian who has been writing about nutrition and health since 2004. Her work has been published in the scientific journal Explore. She holds a Master of Public Health in human nutrition from the University of Michigan.