Vitamin D is primarily a fat soluble vitamin which assists our body in absorbing minerals such as calcium and phosphorus which are stored in the body's fatty tissue. Vitamin D is naturally present in very few foods compared to other Vitamins. In fact, the best natural source of Vitamin D is early morning sunlight. The human body makes vitamin D when it is exposed to ultraviolet B (UVB) rays in the sunlight but needs to undergo two hydroxylation reactions to be activated in the body. Vitamin D found in the body is in the active form of Calcitriol (1, 25-Dihydroxycholecalciferol).