The experimental rations commonly used in studies on the vitamin B2 complex are, as a rule, low in content of choline.
Addition of vitamin B6 has an aggravating influence on the specific effect of deficiency of choline, especially with regard to the development of cortical necrosis of the kidneys.
The acute and subacute lesions associated with this specific type of renal injury are described.
The renal lesions and fat infiltration of the liver, observed in rats kept on a vitamin B free diet, supplemented with thiamine, riboflavin and vitamin B6, are indistinguishable from those attributed hitherto to cystine intoxication.
Attention is drawn to the rôle of choline as a potential member of the vitamin B2 complex and, in this connection, to the importance of the ratio cystine/methionine in the diet.