Differentiation of the Rat Dermatitis Factor and the Chick Dermatitis Factor from Nicotinic Acid

Abstract

Data are presented to show that nicotinic acid will not cure rat dermatitis or prevent chick dermatitis, and it is concluded that vitamin B₆ and the filtrate factor are both distinct from nicotinic acid. The finding of Elvehjem et al. (loc. cit.) that nicotinic acid will cure balcktongue in dogs has been confirmed. These results are regarded as affording direct evidence that the vitamin B₂ complex contains the following four different, sharply characterized entities: riboflavin, nicotinic acid, vitamin B₆ and the filtrate factor.