The determination of vitamin D

Abstract

DYER [1931] has recently described a method of estimation of vitamin D based on the line test. He took 15 litters each consisting of 7 young rats and treated them as follows. Each litter was fed on a rachitogenic diet for 3 to 31 weeks, and the different rats in the litter were then given different doses of a sample of irradiated ergosterol obtained from the National Institute for Medical Research. In each litter 1 rat received no irradiated ergosterol and the others received daily doses of 1 8 j, j,l and 2 units vitamin D respectively. Dosage was continued for 10 days and then the ulnae andradii of the rats were examined