Red cell glutathione reductase saturation obtained with oral riboflavin supplementation

RESUMO

The erythrocyte glutathione reductase (E-GR) saturation with its coenzyme flavin adenine dinucleotide (FAD) affords the nutritional status regarding the vitamin B2, as FAD proceeds from riboflavin intake. E-GR normally exhibits physiological partial saturation with its coenzyme. OBJECTIVE: To study the maximum in vivo saturation which could be reached by increasingly oral vitamin supplemetantion. METHODS: Three groups of normal volunteers were given 3 mg (group A), 20 mg ( group B) and 50 mg (group C) riboflavin daily during twenty days. The enzyme activities were assayed before and after supplementation, with and without coenzyme addition to the reagent system. RESULTS: 77 per cent, 83 per cent and 87 per cent saturation were observed in the groups A, B and C respectively. CONCLUSION: Increasing in vivo saturation was observed with increasing oral doses of riboflavin supplementation, but total saturation was not observed even with the highest oral 50 mg roboflavin supplementation