The Calcium-Phosphorus Relationship in the Nutrition of the Growing Chick

The calcium, phosphorus, and vitamin D requirements of the growing chick and other animals, have been a subject of much research which has led to more or less conclusive results. McCollum and associates,1 as well as Sherman and Pappenheimer,2 have pointed out that the three dietary components, calcium, phosphorus, and vitamin D, or its equivalent, are especially concerned in normal bone formation. These investigators further pointed out that the relative proportions of these three factors, particularly the quantitative relations, between the calcium and phosphorus in the food supply are, within certain limits of concentration, of great significance in determining whether an animal, like the rat, will develop bones which are normal or pathological. Bethke, Steenbock, and Nelson3 pointed out sometime ago, with the rat, that on low calcium rations the amount of cod-liver oil necessary to furnish the antirachitic factor in sufficient amounts varied inversely with the calcium content of . . .