Calcium carbonate oral suspension 1250mg/5 ml - 16 oz.Store at controlled room temperature. Protect from freezing. Prevention of calcium deficiency. It is used as an antacid to relieve the symptoms of indigestion and heartburn. It is also used to prevent osteoporosis, as a calcium supplement, and to treat high phosphate levels in patients with kidney disease. 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.