A list of calcium functions follows:. * Every cell is dependent on the presence of ionic calcium.. * It is used in teeth and bones and the movement of muscles.. * It is required for the rhythmic action of the heart and the. intestines.. * It is essential for the clotting of blood.. * It plays a role in infections, pregnancy,and in the. maintenance of the acid-alkaline balance.. * Its presence or absence is a factor in the formation of. tooth decay, pyorrhea, and the degenerative disease.