Vitamin D

The media-emphasized main conflict surrounding this vitamin (which is actually a hormone, not a vitamin) revolves around sun exposure and whether or not using sunscreen hinders our bodies’ ability to manufacture vitamin D. Vitamin D deficiency can be a serious health problem and sunlight can be the most abundant, natural way for our bodies to create it. But can our bodies utilize the sun to create vitamin D if we regularly use sunscreen? The answer is a resounding yes. Despite news stories to the contrary, several large, controlled studies have shown that vitamin D deficiency does not result from ongoing regular sunscreen use. Aside from sun exposure, vitamin D supplementation is still a good idea because even with sun exposure we can still be deficient. (Sources: The Journal of the American Osteopathic Association, August 2003, pages 3-4; American Journal of Clinical Dermatology, March 2002, pages 185-191; Dermatology, January 2001, pages 27-30; and British Medical Journal, October 1999, page 1066).

You may be wondering what other roles vitamin D plays in maintaining healthy skin. Skin cells, along with the cells of our other major organs, have receptor sites for vitamin D. These sites allow the conversion of vitamin D (via sun exposure) to its active form. Thus far, the most substantiated information pertaining to vitamin D and skin involves its role as a potential treatment for psoriasis and its involvement in the prevention of skin cancers.

If you suffer from psoriasis, you should know that the active form of vitamin D, 1,25-dihydroxyvitamin D3 (also known as calcitriol) can help control the proliferation of skin cells that lead to psoriatic lesions and modulate the immune system’s hyper-response to this disorder. Various topical prescription treatments using vitamin D derivatives are available, but making sure you consume enough vitamin D via diet or supplementation plays a role, too. Vitamin D deficiency, which is actually quite common, can lead to problems with cell growth and differentiation throughout the body, including skin. Some researchers are working to prove that long-term vitamin D deficiency leads to skin malignancies (skin cancer). The protective effects of topically-applied vitamin D analogues (chemical compounds similar to the vitamin D our skin naturally produces in the presence of sunlight) have been demonstrated in-vivo (on a live subject), though studies have been conducted on mouse, rather than human, skin. Understandably, researchers believe that further exploration into how topically-applied vitamin D may protect skin cells from the DNA damage that leads to cancer is worthwhile. In the future, it is possible that sunscreen recommendations will be accompanied by new vitamin D dietary guidelines to ensure proper levels are achieved.

Sources for the above information: The British Journal of Dermatology, October 2005, pages 706-714; Current Rheumatology Reports, October 2005, pages 356-364; Photochemistry and Photobiology, E-Publication, February 1, 2005; The Journal of Steroid Biochemistry and Molecular Biology, E-Publication, July 19, 2005 and Experimental Dermatology, December 2004, page 11).

Paula Begoun

For more detailed information on this topic, see Paula’s article, Vitamin D and Sun Exposure.