Calcium-Phosphorus Metabolism in the Chicken

The purpose of this paper is to review the recent work dealing with calcium and phosphorus metabolism and to report certain experiments on this problem. It is known that both rickets and hypervitaminosis are related in some way to a disturbed calcium-phosphorus metabolism. Closely associated with this disturbance is the influence exerted on the organism by cod liver oil, sunlight, and the more recently discovered ergosterol. It is now established that there are four factors, calcium, phosphorus, vitamin D and radiation, the lack of any one of which plays an important part in the production of rickets. According to Park8 rickets is a disturbance in the metabolism of the growing organism of such a nature that the salt equilibrium, in particular as regards calcium and phosphorus in the circulatory fluids, is disturbed and lime salts no longer deposit in the bones. In 1923 Hart, Halpin, Steenbock and Lepkovsky10 showed that . . .