<unk>  is an antacid that is FDA approved for the treatment of heartburn, sour stomach, acid indigestion, upset stomach associated with these symptoms.   Common adverse reactions include constipation, flatulence, swollen abdomen.<unk>  is a chemical compound, with the chemical formula<unk> . It is a common substance found as rock in all parts of the world, and is the main component of shells of marine organisms, snails, and eggshells.<unk>  is the active ingredient in agricultural lime, and is usually the principal cause of hard water. It is commonly used medicinally as a<unk>  supplement or as an antacid.
Calcium carbonate
Calcium acetate
Calcium sulfate
Strontium ranelate
Calcium fluoride
Ferrous carbonate
Magnesium carbonate
Calcium arsenate