The determination of vitamin D

Abstract

A scale is described for correlating doses of a standard soln. of irradiated ergosterol, administered prophylactically, with the percentage ash in the bones of young rats on a rachitogenic diet. When the values for the percentage ash were plotted against the logarithms of the doses, a linear relationship between the two variables resulted, showing that as the doses were increased in geometrical progression the calcification increments advanced arithmetically. Twenty litters of rats were used and they were divided into a more and a less rachitic series of 10 litters each.