One of the world’s leading vitamin D advocacy groups this week called for the public to realize that the Sunshine Vitamin’s role in activating the body’s immune system is far-beyond theoretical and has an explained and understood mechanism.

The non-profit Vitamin D Council, in a letter titled “The Difference Between a Prophet and a Madman” published in the British Journal of Nutrition and reprinted on the Vitamin D Council’s web site, this week called for the public to realize that the link between natural vitamin D levels and increased immunity can no longer be called folly. In scientific terms, Vitamin D Council President Dr. John Cannell, MD, laid out the mechanism by which the Sunshine Vitamin assists immunity.

“The mechanism of action of vitamin D in preventing and treating various infections, a mechanism that led Science News to characterize vitamin D as the ‘the antibiotic vitamin’ has become evident only very recently. Both epithelial cells and macrophages increase expression of the antimicrobial cathelicidin upon exposure to microbes, an expression that is dependent upon the presence of vitamin D. Pathogenic microbes, much like the commensals that inhabit the upper airway, stimulate the production of a hydroxylase that converts 25(OH)D to 1,25(OH)2D, a seco-steroid hormone. This, in turn, activates a suite of genes involved in defense,” Cannell wrote.

He continued, “In the epidermis, vitamin D induces additional PAMP (pathogen associated molecular pattern) receptors, enabling keratinocytes to recognize and respond to microbes. Thus, vitamin D appears to both enhance the local capacity of the epithelium to produce endogenous antibiotics and – at the same time – dampen certain arms of the adaptive immune response, especially those responsible for the signs and symptoms of acute inflammation.”

To read all of Cannell’s article click here.