Effect of vitamin B₆ on leucine-induced changes in human subjects

Abstract

Distrubances in the tryptophan-niacin pathway seen in endemic pellagra among sorghum eaters have been ascribed to high dietary intake of leucine. Vitamin B₆ plays an important role in several steps of this pathway. Therefore, studies on possible metabolic interrelations between excess dietary leucine and vitamin B₆ were undertaken in normal healthy human subjects. The results indicated that vitamin B₆ could successfully counteract the effects of leucine on quinolinic acid excretion in urine, and on in vitro nicotinamide nucleotide synthesis by erythrocytes, and also could correct the abnormalities of 5- hydroxytryptamine metabolism induced by excess leucine. These observations suggest that vitamin B₆ nutritional status may have a contributory role in the pathogenesis of endemic pellagra.