By: Marc Sorenson, Sunlight Institute–
Vitamin D has a multitude of health benefits, and the only natural way to obtain vitamin D is from sunlight exposure, which causes the skin to produce vitamin D3. The D3 is then is converted to a potent hormone that “turns on” more than 1,000 genes in the genetic engine. As I studied the scientific literature regarding vitamin D and sunlight, I noticed, however, that the strongest and most consistent health benefits were often related more closely to sunlight exposure per se, than to vitamin D supplementation or vitamin D blood levels. Some of my earliest observations regarded prostate cancer and osteoporosis, where vitamin D supplementation and high blood levels of vitamin D seemed generally effective, but exposure to sunlight was profoundly effective.
I also noted that vitamin D supplementation seemed to decrease osteoporotic fractures, but sunlight exposure could actually reverse the disease. (See my previous post). And of course, we know that sunlight or other ultraviolet light exposure dramatically enhances mood.
One of the latest studies to corroborate my observations was published in the European Journal of Cancer in December, 2012, and was entitled, is prevention of cancer by sun exposure more than just the effect of vitamin D? A systematic review of epidemiological studies.[i] In their review, the authors noted that regular sunlight exposure correlated to a reduced risk of colorectal cancer, prostate cancer, breast cancer and non-Hodgkin’s lymphoma (NHL). However, vitamin D levels correlated to a reduced risk of colorectal, and to a lesser extent, breast cancer, but were not correlated to a significant risk reduction in prostate cancer and non-Hodgkin’s lymphoma. The authors concluded with this statement: “Particularly in prostate cancer and NHL, other sunlight-potentiated and vitamin D-independent pathways, such as modulation of the immune system and the circadian rhythm, and the degradation of folic acid, might play a role in reduced cancer risk as well.”
The authors could have also mentioned the effect of sunlight on vasodilation, mediated by the production of nitric oxide (produced by the skin after sunlight exposure). They could also have discussed the influence of sunlight on production of serotonin and endorphins. These effects have nothing to do with vitamin D, and future research will determine whether these “beyond-vitamin D” effects also reduce the risk of various cancers.
Vitamin D is an exceptionally important product of sunlight, but it is hardly the only product. I predict that a whole new field of research on other photoproducts of sunlight exposure will soon emerge and provide impressive new knowledge regarding the life-and-health giving benefits of our most precious friend, the sun.
[i] van der Rhee H, Coebergh JW, de Vries E. Is prevention of cancer by sun exposure more than just the effect of vitamin D? A systematic review of epidemiological studies. Eur J Cancer. 2012 Dec 10. pii: S0959-8049(12)00885-4. doi: 10.1016/j.ejca.2012.11.001. [Epub ahead of print] <?xml:namespace prefix = o />