The examination of yeast-fat for the presence of vitamins A and D before irradiation and of vitamin D after irradiation

Abstract
No vitamin A was found in yeast fat, when a daily dose of 0.18 gm. was given to rats on a diet deficient only in vitamin A. Another sample of yeast fat was devoid of vitamin D before irradiation, when a daily dose of 0.14 gm. was given. When irradiated, a daily dose of 0.005 mgm. of the yeast fat was sufficient for rats. The quantitative relationship of the vitamin D in the irradiated fat to the ergosterol and zymosterol present in the fat before irradiation was not worked out.