Not Medical Advice. A round, pink pill with “RP 102” on it is 750 mg of calcium carbonate, an antacid. Calcium carbonate is a dietary supplement used when someone is not getting enough calcium from their diet. Calcium is needed by the body for healthy bones, muscles, nervous system, and heart.
Calcium carbonate is also used as an antacid to relieve heartburn, acid indigestion, and upset stomach. It is sold under brand names like Tums, Maalox, and Rolaids.
Most people use calcium carbonate for the first time in the classroom, as chalk; it has been used as a writing tool for over 10,000 years.