Corcium Tablet contains coral calcium 225mg and 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 the intake of calcium is necessary to keep the bones strong.