The incorporation of calcium into bones, teeth and various organs, as well as the rate of its secretion from the organism of experimental rats was investigated using per os administration of 45Ca salts of phosphatidic acids present in a commercially available emulsifier. It was proved that the utilization of calcium from this preparation is satisfactory and up to a dose 1.2 g/kg of body weight is quite comparable with that of CaC12. The emulsifier can be used as a supply of calcium for the fortification of foodstuffs