Calcium carbonate is a dietary supplement used when the amount of calcium taken in the diet is not enough. Calcium is needed by the body for healthy bones, muscles, nervous system, and heart. Calcium carbonate also is used as an antacid to relieve heartburn, acid indigestion, and upset stomach.
Calcitriol is a form of vitamin D3. Vitamin D helps your body absorb calcium from the stomach.
Its main roles are to support calcium metabolism and prevent calcification of the arteries.