Coral Calcium Vitamin D3 Tablets is a dietary supplement that contains calcium, vitamin D3, and other minerals derived from coral reefs. Calcium is an essential mineral that is important for strong bones and teeth, nerve function, and muscle contraction. Vitamin D3 helps the body to absorb calcium and is also important for immune function and bone health. Coral calcium is a form of calcium that is derived from fossilized coral reefs. It is believed to be more easily absorbed by the body than other forms of calcium.