Riboflavin nutritional status and absorption in oral contraceptive users and nonusers.

Riboflavin nutritional status and its oral absorption was investigated in 2 groups of women -- a group of 18 oral contraceptive (OC) users and a control group of 17 women. The riboflavin nutrition status was based on erythrocyte glutathione reductase (EGR) determinations. Prior to administration of test doses of riboflavin mean EGR levels of 4.96 (OC group) and 4.44 (control group) umoles glutathione reduced per minute per gram of hemoglbin were not significantly different. After oral administration of riboflavin there was a significant increase in EGR levels within each group but no significant differences between groups. Mean EGR levels continued to be slightly lower for the OC group compared to the control group. Oral absorption of riboflavin based on urinary excretion results was not significantly different between the groups. The findings indicate that OC use does not significantly affect riboflavin nutritional status in a subject population of moderate to high socioeconomic status that has adequate nutrition. The significant reductions in EGR levels which have been previously reported for OC users seem to be associated with a low socioeconomic status.