Abstract
A modification of the USP chemical method for vitamin D has been studied collaboratively. Included in the study were four samples, varying from 150 to 100,000 International Units per gram: a fortified chick feed, a fortified evaporated milk, a high potency concentrate, and a fish liver feeding oil. Results by the chemical estimation are compared with those on the same samples by the AOAC rat bioassay, and, when applicable, by the AOAC chick bioassay. The mean results of the chemical assays were 75—100% of the bioassay results. Further modifications of the chemical method to ensure applicability to feeds and foods in the range of 5—95 units per gram should be studied collaboratively.
THE REACTION OF THE CHICKEN TO IRRADIATED ERGOSTEROL AND IRRADIATED YEAST AS CONTRASTED WITH THE NATURAL VITAMIN D OF FISH LIVER OILS