Vitamin D3 also known as Cholecalciferol is present in Nano in 200 IU strength. It is a fat soluble vitamin, essential in calcium and phosphorus metabolism. It helps in absorption of Ca and P from food in the small intestine. It is synthesized in human body upon exposure to sunlight and ultraviolet radiation. Due to lack of the same, the deficiency occurs and then it needs to be supplied from outside sources. Fatigue, general debility and convalescence are such stages needing this vitamin and NANO is the best supplement to supply these in desired amount.