Metabolic Studies of Mongoloids

Abstract

The metabolism of a number of water-soluble vitamins by mongoloid and non-mongoloid, all mentally deficient children, has been studied. Relatively little differences in the excretion of thiamine, riboflavin, niacin, N-methylnicotinamide and vitamin C were observed prior to vitamin load tests. Following the load tests no significant difference was observed in the excretion of riboflavin by mongoloids and non-mongoloids and the excretion of thiamine although slightly greater in mongoloids was not marked. The administration of 100 mg of nicotinamide resulted in significantly less excretion of ɴ-methylnicotinamide and creatinine by mongoloids than non-mongoloids. The possibility of a defect in the methylating ability of mongoloids has been suggested. Following the feeding of 5 g of ᴅ ʟ-tryptophan, significant differences in $-methylnicotinamide and creatinine excretion were not observed, but the excretion of xanthurenic acid was lower in mongoloids than non-mongoloids.