Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the two most important compounds in this group are vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol).Vitamin D, a fat-soluble vitamin, acts in the calcium and phosphorus metabolism in its active form (1,25-dihydroxy vitamin D). It may help prevent and treat autoimmune diseases, including diabetes mellitus.Many studies have looked at the role of vitamin D in diabetes and have shown an association between low levels of vitamin D and increased risk for Type II diabetes and