Does Vitamin A Possess Vitamin D-Sparing Properties When Fed to Growing Chicks?

THE work described in this paper was stimulated by the work of Massengale and Nussmeier (1930), Hess and Supplee (1920), and Mussehl and Ackerson (1930) who advanced experimental evidence to show that cod liver oil is more effective in preventing nutritional legweakness in chicks than equivalent amounts of activated ergosterol, as measured by the rat method of assay for vitamin D. Since the vitamin A content of the rickets-producing ration is ordinarily dependent on the quality and quantity of yellow corn present, it was thought that the superiority of cod liver oil for growth and ossifying potency might be due, at least in part, to the ample amount of vitamin A, which is characteristic of cod liver oil. As a result, the following experiments were conducted with the view of amplifying the legweakness producing ration with vitamin A to determine whether or not this vitamin possesses vitamin D-sparing properties. Experimental . . .