Riboflavin requirements of lactating Gambian women: a controlled supplementation trial.

As part of a study to determine the minimum allowance of riboflavin which is adequate for lactating women in a rural African environment 60 subjects living in 2 Gambian villages were either given 2 mg riboflavin or a placebo daily on a double-blind basis for 12 weeks. Their riboflavin intake from dietary sources was about 0.5 mg/day. In the supplemented group the mean activation coefficient (AC) of erythrocyte glutathione reductase fell from 1.62.1.19 within 3 weeks and 90% had mean ACs below 1.3 throughout supplementation whereas the placebo group maintained mean ACs between 1.6-1.9. Clinical signs associated with riboflavin deficiency improved more rapidly in the supplemented group; their breastmilk riboflavin levels increased and their infants ACs were reduced compared with those of the placebo group. After withdrawal of the supplement the maternal and infants ACs rose toward those of the placebo group. Thus a total riboflavin intake of about 2.5 mg/day during lactation is sufficient to maintain normal biochemical status in most Gambian women. (authors)