The Interrelationship of Calcium, Phosphorus and Nitrogen in the Metabolism of Pre-School Children

Abstract

Five pre-school children received, during 15- to 24-day periods, diets containing first, 3 and then 4 gm. of protein per kilogram of body weight. For two children whole egg, meat and milk increased the nitrogen content of the diet while for the others egg white and gelatin were used. The higher protein diet had no effect on calcium absorption or retention. It caused a decrease in the absorption of phosphorus but there was a better utilization of the amount available. There was an increase in both nitrogen absorption and retention. Weight gains were greater on the 4- than on the 3-gm. protein diet and represented different types of tissue growth. Decided increases in nitrogen retentions and significant changes in retention ratios for Ca:P, N:Ca, N:total P and N:non-osseous P, suggested that muscle and other soft tissue accounted for the greater proportion of the increased weight gains. There may have been additional bone growth in three children who had increased calcium retentions.