Power D3 contains Cholecalciferol 1000 iu (International units). Cholecalciferol (Vitamin D3) which is a fat soluble vitamin that helps the body to absorb calcium and phosphorous found in food and supplements. Vitamin D is made by the body when skin is exposed to sunlight. Sunscreen protective clothing limited exposure to sunlight dark skin and age may prevent getting enough vitamin D from the sun thus leading to Vitamin D3 Deficiency. Thus Vitamin D3 in Power D3 capsule is essential for calcium absorption in the body. Other uses of Power D3 capsule are: Building and keeping the bones & teeth strongReducing Fatigue/stress and muscular painsBoosting immunity and increasing resistance against infectionSupplement for patients with diabetic complications and Cardio Vascular Diseases as well. Use under medical supervision.