Effect of Carbon Dioxide on Calcium and Phosphorus Retention

It is well known that the administration of acids or of potentially acid salts, such as ammonium chloride, to animals often leads to decalcification. Apparently several factors are involved, such as the age of the animal, the calcium intake, and the disturbance in the acid-base equilibrium. Burns (1) fed hydrochloric acid to rabbits and rats and found that it retarded growth, increased the water content, and decreased the fat content of the bones. No evidence of calcium withdrawal from the bones was obtained. Chute and Irving (2) administered 5 cc. of 2 N HCI daily to rats and found that the Ca:C03 ratio of the bones was increased, indicating that calcium carbonate was probably removed in excess of phosphates. This effect was more pronounced in those animals receiving the diet for only a few days. Apparently compensatory mechanisms are brought into play when the acid administration is carried on for some time. Lamb and Evvard (3) were unable to show any deleterious effect on swine, weighing about 125 pounds, from the daily administration of 200 cc. of N HzS04. Rabbits were able to stand 5 cc. of N H,SO, daily but succumbed to greater amounts. Rats grew and reproduced normally on a diet containing a potential acidity of 15 cc. of normal acid per 100 gm. of food. Jaffe, Bodansky, and Chandler (4) found that the decalcifying action of ammonium chloride could be reduced by the administration of calcium salts. Cod liver oil was quite ineffective in preventing this decalcification, especially in the case of young rats on a low calcium diet. The effect of the ammonium chloride was also found to diminish very materially as soon as the animal passed the young puppy stage.