The properties of Vitamin D
Vitamin D is a fat-soluble vitamin synthesized in epidermal keratinocytes. Vitamin D obtained from the diet or synthesis in skin is inactive and needs to be activated enzymatically. Serum levels are primarily maintained through the UVB-mediated conversion of 7-dehydrocholesterol in the skin to cholecalciferol, which is hydroxylated in the liver and kidney to the active form of 1,25-dihydroxyvitamin D [1,25(OH)2D]. There is strong evidence that vitamin D exerts an anti-inflammatory and immunoregulatory effect, in addition to its important role in maintaining adequate serum levels of calcium and phosphorus.
