Corcium D3 tablet contains coral calcium and Vitamin D3. Coral calcium is composed primarily of calcium carbonate with small amounts of magnesium and other trace minerals. Coral has a chemical structure that is very similar to the composition of human bone. Calcium plays a very important role in the body. It is necessary for normal functioning of nerves, cells, muscle, and bone. If there is not enough calcium in the blood, then the body will take calcium from bones, thereby weakening bones. Thus intake of Calcium is necessary to keep the bones strong. Vitamin D helps the body absorb calcium and phosphorus. Having the right amounts of Vitamin D, Calcium, and Phosphorus is important for building and keeping strong bones.