Vitamin D and its metabolites
Vitamin D is a fat-soluble vitamin that animals obtain naturally from the metabolite 7-dehydrocholesterol when exposed to the sun. This metabolite is found in the membrane of the cells of the dermis and epidermis and is transformed into cholecalciferol or vitamin D3 by the effect of ultraviolet light, being released into the extracellular space and subsequently passing into the bloodstream.
1,25-dihydroxyvitamin D3, active metabolite of vitamin D3, is a necessary factor for the absorption, transport and utilization of calcium and phosphorus and, therefore, essential for bone formation in warm-blooded animals.
In the following article we explain the detail of Vitamin D and its metabolites.