In Vitro Solubility Characteristics of Six Calcium Salts.

Six calcium salts (lactate, carbonate, citrate, gluconate, phosphate, and citrate malate) were evaluated for ionic and total soluble calcium content utilizing a sequential pH treatment to simulate gastrointestinal pH conditions. At pH 2.0 (gastric pH), 80-90% of all soluble calcium present was in the ionic form.