Dissolution of biologically important sparingly soluble salts, such as calcium carbonate and calcium oxalate, is possible by use of carboxyl- and carboxyl/phosphonate-bearing, anionic additives, citrate, malate, carboxyphosphonate, and butane tetracarboxylate. Calcium-containing dissolution products have been identified, characterized, and independently synthesized. These are polymeric materials composed of calcium and the additive as the ligand. Their full characterization was carried out by single-crystal X-ray crystallography and other techniques.