Possible vitamin B 6 deficiency in nigerian young adults: Assessment by xanthurenic acid excretion

Abstract

Vitamin B 6 status was assessed from urinary xanthurenic acid (XA) excretion in 34 male and female university students in Nigeria. Urinary XA excretion was measured following a 5g L-tryptophan load administered before (pre-pyridoxine) supplementation. About 95% of the females and 35% of the males excreted above 150 umoles XA/24hr (indicative of vitamin B 6 deficiency) after tryptophan loading. Supplementation with 25mg pyridoxine hydrochloride for 2 days significantly reduced XA excretion in all subjects; the reduction was more significant for females than males. In view of the wide-spread deficiency of riboflavin in Nigeria, and the involve-of riboflavin in pyridoxine metabolism, it is speculated that riboflavin status in addition to hormonal influence (in females) may account for the high occurrence of vitamin B 6 deficiency in these subjects.