Calciferols are group of lipid soluble compounds with a 4-ringed cholestoral backbone and refer to both, Vitamin D3 i.e. Cholecalciferol and Vitamin D2 i.e. ergocalciferol. In general as Vitamin D3 is the active component of Vitamin D whether reference of Vitamin D comes, we used Vitamin D3 as a terminology, Vitamin D mainly near about 90 % is synthesized in the sun under sun exposure, Vitamin D is useful in maintaining the normal levels of calcium and phosphate that are required for normal mineralization of bone, muscle contraction nerve, conduction and general. Cellular function in all cells of the body. In India, in various studies, it is observed that in healthy asymptomatic people show low values of Vitamin D inspite of exposure to sufficient sun rays, proper diet intake. Age, sex, geographical situation, these factors not affecting the value of Vitamin D.

Keywords : Vitamin D, Cholecalciferol, Sources of Vitamin D, Rickets, Osteomalacia, Cut off values, Epidemic of Vitamin D, Deficienty, prevention at Nation level.