The Influence of Orally Administered Calcium Salts on the Serum Calcium of Normal and Thyreoparathyroprivic Dogs

Calcium is a very important constituent of the body tissues, not only in making up the bony skeleton but also in maintaining certain nervous and muscular equilibria.Calcium equilibrium is well maintained in health by the ordinary foods.The calcium salts are absorbed, and transported through the body in various forms.It may be combined as bicarbonate, phosphates, proteinates, and perhaps hexose phosphates as suggested by Robison (1).The preservation of equilibrium in the tissues is ample evidence of calcium absorption in the alimentary canal.The actual process of absorption has led to considerable discussion depending on the acceptance of certain governing factors.An excess of phosphate or alkali would naturally limit absorption by converting the calcium into relatively insoluble salts.Givcns (2) noted an increase in calcium elimination in the stools when fats and fatty acids were poorly utilized.He (3) also demonstrated that the form in which calcium was ingested influenced absorption, for the amount of calcium absorbed from milk exceeded that from calcium lactate when both were given in like quantity as calculated by their calcium contents.In health and with ordinary foods the required amount of calcium is absorbed in spite of the presence of interfering agencies.Such is not the case in certain diseases.In rachitis, in which Schabad (4), Schloss (5), and Orr (6) have shown a calcium and phosphorus deficiency, these two elements are poorly absorbed.Zucker and Matzner (7) in their observations on the pH of the intcst.inalcontents of rachitic