Vitamin D

Vitamin D is an essential fat-soluble vitamin. Good food sources of vitamin D include: certain fish such as: salmon, mackerels, and sardines.1 Vitamin D can also be found in fortified milk and breads as well as fruit juices.1

Solar Ultraviolent (UV) light stimulates the production of Vitamin D in the skin. It is estimated about 15 minutes of sun exposure around noon on a sunny day during Spring, Summer, and Autumn is sufficient for the daily Vitamin D requirement.2 However, using sunblock with SPF factor of 10 or higher will reduce Vitamin D production substantially.3

The 100% Daily Value for Vitamin D (based on a 2,000 kcal diet) is 400 IU* (=10 mcg), but it has been revised to 20 mcg as of May 27, 2016.13 The 100% Daily Value for pregnant or lactating women is 15 mcg, effective as of January 1st, 2020.13

*IU stands for International Unit; Vitamin D unit changed from IU to mcg by FDA. (effective January 1st, 2020)4,13

Forms

  • Vitamin D3: Vitamin D3, also known as cholecalciferol, is a bioavailable form of vitamin D. Vitamin D3 can be derived from 7-dehydrocholesterol, extracted from the natural fat found in lamb’s wool. Vitamin D3 is the same type of vitamin D formed in human skin through exposure to natural sunlight.

Major Health Benefits

Vitamin D helps the absorption of calcium and phosphorous. Thus, Vitamin D is critical for proper formation and maintenance of healthy bones, teeth, and muscular function.5-7 Vitamin D also contributes to the normal function of the immune system and may help prevent the development of autoimmunity in some autoimmune disorders such as: type 1 diabetes, multiple sclerosis, and rheumatoid arthritis.8-11 Vitamin D also plays a role in increasing cell division (differentiation) leading to cancer prevention.5 Deficiency of Vitamin D can lead to rickets in children and infants, and muscle weakness and pain, excessive production of parathyroid hormone (PTH), and bone breakdown.9,12

References

  1. Higdon, J. Vitamin D. Linus Pauling Institute, Oregon State University. 2000. (Reviewed by Gombart, AF in 2014). http://lpi.oregonstate.edu/mic/vitamins/vitamin-D Accessed 7/2015.
  2. Terushkin V, Bender A, Psaty EL, Engelsen O, Wang SQ, Halpern AC. Estimated equivalency of vitamin D production from natural sun exposure versus oral vitamin D supplementation across seasons at two US latitudes. J Am Acad Dermatol. 2010 Jun;62(6):929.e1-9. PMID: 20363523.
  3. Balk SJ; Council on Environmental Health; Section on Dermatology. Ultraviolet radiation: a hazard to children and adolescents. Pediatrics. 2011 Mar;127(3):e791-817. PMID: 21357345.
  4. US Food and Drug Administration. Guidance for Industry: A Food Labeling Guide (14. Appendix F: Calculate the Percent Daily Value for the Appropriate Nutrients). US Department of Health and Human Services. 2013 January. http://www.fda.gov/Food/GuidanceRegulation/GuidanceDocumentsRegulatoryInformation/LabelingNutrition/ucm064928.htm
  5. European Food Safety Authority. Scientific Opinion on the substantiation of health claims related to vitamin D and maintenance of bone and teeth, absorption and utilization of calcium and phosphorus and maintenance of normal blood calcium concentrations, cell division, and thyroid function. EFSA Journal 2009; 7(9):1227.
  6. European Food Safety Authority. Scientific Opinion on the substantiation of health claims related to vitamin D and normal function of the immune system and inflammatory response, maintenance of normal muscle function and maintenance of normal cardiovascular function. EFSA Journal 2010;8(2):1468.
  7. European Food Safety Authority. Scientific Opinion on the substantiation of health claims related to calcium and vitamin D and maintenance of bone. EFSA Journal 2009;8(2):1272.
  8. Higdon, J. Vitamin D. Linus Pauling Institute, Oregon State University. 2000. (Reviewed by Gombart, AF in 2014) (Autoimmune Diseases)
  9. Higdon, J. Vitamin D. Linus Pauling Institute, Oregon State University. 2000. (Reviewed by Gombart, AF in 2014) (Deficiency)
  10. Holick MF. Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis. Am J Clin Nutr. 2004 Mar;79(3):362-71. PMID: 14985208.
  11. Volmer DA, Mendes LR, Stokes CS. Analysis of vitamin D metabolic markers by mass spectrometry: current techniques, limitations of the “gold standard” method, and anticipated future directions. Mass Spectrom Rev. 2015 Jan-Feb;34(1):2-23. PMID: 24318020.
  12. Jones AN, Hansen KE. Recognizing the musculoskeletal manifestations of vitamin D deficiency. J Musculoskelet Med. 2009 Oct;26(10):389-396. PMID: 21984863; PMCID: PMC3188408.
  13. US Food and Drug Administration. Food Labeling: Revision of the Nutrition and Supplement Facts Labels. US Department of Health and Human Services. Federal Register / Vol. 81, No. 103, p. 33982 / May 27, 2016. https://www.gpo.gov/fdsys/pkg/FR-2016-05-27/pdf/2016-11867.pdf