By Marc Sorenson, EdD, Sunlight Institute
In a new media release from Toronto, the Vitamin D Society asserts that “The importance of natural sunlight to human life cannot be understated.” It goes on to quote Dr. Reinhold Vieth, a scientist and professor at the University of Toronto. “There really is no substitute for natural sunlight in human health. Your skin is like a solar receptor and has the amazing capacity to manufacture all of the vitamin D your body needs. Everyone has the capability to generate vitamin D.”
There is a problem, however, as I posted recently. About a third of Canadians, about 12 million people, do not meet the minimum Health Canada guidelines for vitamin D levels. The reason? Sunlight deficiency.
Perry Holman, executive director of the Society, states that “This is not a call for people to ignore the warnings about over-exposure to sunlight but a call for people to exercise common sense and ensure they are not shutting themselves out from the vital health benefits of natural sunlight.”
Of course, in the winter, when no vitamin D production is available, it will be necessary to find another source of vitamin-D stimulating light. Sunlamps are ideal, provided they produce UVB light.
Also remember, that during winter, sunlight still raises serotonin levels and produces nitric oxide, both of which are necessary to human health. The value of sunlight goes far beyond its ability to promote vitamin D production in the skin.
For more information on the Vitamin D Society, visit www.vitamindsociety.org.
By Marc Sorenson, EdD
Drs. Asta Juzeniene and Johan Moan wrote a paper in 2012 that beautifully summarizes the effects of sunlight beyond the production of vitamin D. Here are the highlights of their paper, as stated in the abstract. They discuss the separate affects of Ultraviolet B light (UVB) and ultraviolet A light (UVA), which are, of course, components of sunlight.
- UVB induces cosmetic tanning (immediate pigment darkening, persistent pigment darkening and delayed tanning).
- UVB-induced, delayed tanning acts as a sunscreen.
- Several human skin diseases, like psoriasis, vitiligo, atopic dermatitis and localized scleroderma, can be treated with sunlight or artificial UV radiation (phototherapy).
- UV exposure can suppresses multiple sclerosis independently of vitamin D synthesis.
- UVA generates nitric oxide (NO), which may reduce blood pressure and generally improve cardiovascular health.
- UVA induced NO may also have antimicrobial effects.
- UVA induced NO may act as a neurotransmitter.
- UV exposure may improve mood through the release of endorphin.
It wasn’t mentioned in the paper, but we now know that sunlight also helps generate serotonin in the brain, which improves mood, and outside the body it is a potent disinfectant (see my recent blogs on those subjects). So those who claim that sunlight is harmful in any amount, must be living on a different planet. Embrace the Sun, but never burn.
 Asta Juzeniene and Johan Moan. Beneficial effects of UV radiation other than via vitamin D production. Dermato-Endocrinology 4:2, 109–117; April/May/June 2012.