Can vitamin D replace the sun?

Posted on Mon, 10 Sep 12

It is clear that we are not getting enough sun and most people are seriously vitamin D deficient but does taking vitamin D replace the benefits of sunlight? 

Lack of sunlight exposure has been associated with a host of serious illnesses and currently the popular belief is that this is because of inadequate production of vitamin D. Though a study published in 2010 cast a shadow of doubt on the vitamin D connection.

Researches found that UV radiation has effects independent of vitamin D. They discovered that UV radiation was able to reduce the activity of the immune system in an experimental model of multiple sclerosis, an autoimmune disease known to be related to low sun exposure.

Unfortunately it is very difficult to separate the effects of UV radiation from vitamin D as it is what triggers vitamin D synthesis in the skin. A recent review on the beneficial effects of UV radiation however points out that sunlight may have benefits other than vitamin D production such as increased skin melanin (which may help skin diseases), raised nitric oxide (which could benefit heart health) and boosting beta-endorphins (which could improve mood).

While treating vitamin D deficiency will undoubtedly remain very important, perhaps we should consider bringing back heliotherapy (sunlight exposure), a medical practice that was used to treat illness in ancient Egypt, Greece and Rome.

References:

1. Becklund BR, Severson KS, Vang SV, DeLuca HF. UV radiation suppresses experimental autoimmune encephalomyelitis independent of vitamin D production. Proc Natl Acad Sci U S A. 2010 Apr 6;107(14):6418-23.

2. Juzeniene A, Moan J. Beneficial effects of UV radiation other than via vitamin D production. Dermatoendocrinol. 2012 Apr 1;4(2):109-17.