Effects of dietary protein and calcium on the skeleton of undernourished young rats.

A study has been made of the effects of various levels of dietary protein and calcium on the skeleton of young undernourished rats. The data for the study were obtained from physical properties of bone, from microradiographs of various parts of femur and histological sections of the bone. There were significant associations between a low protein intake and low bone mass, irrespective of calcium intake, and between a high protein intake and a high bone density at a normal calcium content of the diet. The influence of dietary protein on the composition of the bone was dependent on the calcium intake. Reduction in the protein level was associated with less trabecular bone and reduction in the calcium reduced mainly the amount of cortical bone.