Summary Solubility of tricalcium citrate has been determined at 21 and 95° C. by dissolution in water and by precipitation from supersaturated solutions containing various proportions of calcium to citrate and at pH 4.4 to 8.8. Solubility product in solutions at equilibrium varied with ionic strength, according to the relation pks = 17.63 − 10.84 μ , but was unaffected by variations in pH and temperature and by the presence of magnesium or phosphate ions. Milk ultrafiltrates were shown to be saturated with tricalcium citrate, i.e., the calculated pk s values agreed with the solubility product in all but two of the 15 samples tested, and composition of two ultrafiltrates was unaffected by agitation with crystals of tricalcium citrate
