STUDIES OF CALCIUM AND PHOSPHORUS METABOLISM

Abstract

In the course of our studies in calciulm metabolism evidence has steadily accumulated that the metabolism of acid-producing substances plays an important r6le in influencing the assimilation and excretion of calcium. This effect, however, has not been adequately studied in man, and in other studies of calcium exchange the potential acidity or alkalinity of foods and medication has largely been neglected. It is the purpose of the present investigation to follow the effect of food-stuffs and inorganic salts on calcium metabolism with relation to their potential acidity (after oxidation) referred to the hydrogen ion concentration of the blood. Studies in rickets for some time have indicated the importance of acidity to the assimilation and storage of inorganic salts in bone. Thus, McClendon (1) noted that the addition of alkali to a diet increased its power to produce rickets and, conversely, Zucker, Johnson, and Barnett (2) reported that the change in acidity of diets from the alkaline toward the acid side of neutrality might result in healing of the rachitic lesions. Much work, too, has been done upon the effect of administered acid on the mineral excretion. The experiments of Givens and Mendel (3) and of Givens (4) upon the effect of base and acid on the general metabolism tended to minimize variations in calcium excretion resulting from this factor. Subsequently, Goto (5), using rabbits, demonstrated depletion of the skeleton by repeated doses of hydrochloric acid. Lamb and Evvard (6) demonstrated increased urinary calcium