The dual nature of water-soluble vitamin B. II

Abstract

The authors present additional evidence proving the existence of 2 separate nutritional factors in the water-soluble vitamin B complex. They adopt the nomenclature provisionally adopted by the British Biochemical Society, viz.: Vitamin B1, denoting the antineuritic, less heat-stable factor; Vitamin B2, denoting the more heat-stable factor, deprived of which young rats fail to grow, and suffer from dermatitis. The dermatitis, loss of hair, and other effects of vitamin B2 deficiency on the young growing rat are described. Stress is laid on the importance of a high degree of purification of the caseinogen used in the basal diet, since this protein is usually contaminated with traces of vitamin B2. Vitamin B1 was supplied by Peters'' antineuritic concentrate prepared from yeast. A method for the assay of vitamin B2 is described.