Vitamin D is a fat-soluble vitamin that helps our body absorb calcium and phosphorus. Having the right amount of vitamin D, calcium, and phosphorus is important to build and keep strong bones. Vitamin D3 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 D3 from the sun. Our Vitamin D3 formula is designed to ensure your body receives an adequate supply.