The Effects Produced by an Increase in the Calcium and Phosphorus Content of the Diet on the Calcium and Phosphorus Balance and on Various Bodily Constituents of the Rat

Abstract

When large amounts of calcium and phosphorus were added to the rations of albino rats practically all the excess calcium was recovered in the feces, whereas the phosphorus in the feces was considerably less than the excess intake. The kidneys were therefore called upon to excrete very little more calcium but much more phosphorus than on the control ration. A small portion of the excess of absorbed calcium but none of the phosphorus was stored in the body. The percentage gain in body weight was not affected by the high calcium-phosphorus intake. The dry weight of the body, however, was definitely lower. The fat content of the body was significantly reduced by the increased intake of calcium and phosphorus. The diminution in the total fat and dry weight was approximately the same. Both the fat and dry weight of the body showed a progressive decline with a progressive increase in the calcium-phosphorus intake. The large amount of calcium and phosphorus interfered to a slight extent with the absorption of food material as shown by combustion of the feces. The effect on absorption, however, could account only in a small degree for the diminution in the fat content of the body.