Riboflavin status: Dietary intake, urinary excretion, and erythrocyte glutathione reductase coefficient activity of female university students

Abstract

The riboflavin status of 58 healthy, non-pregnant female university students was investigated. Riboflavin nutriture was assessed by using dietary intake and biochemical data. Riboflavin intakes were calculated from three-day diet records using a computer program based on nutrient values from Agriculture Handbook No. 8. Urinary riboflavin (24 hr) was determined by fluorometric analysis. Erythrocyte glutathione reductase activity coefficients (EGRACs) were obtained using the automated flavin adenine dinucleotide-dependent glutathione reductase assay. The mean riboflavin intake was 1.39±0.49 mg/day (mean±SD). The mean urinary riboflavin was 0.44±0.32 mg/day, and the mean EGRAC was 1.21±0.12. There was a significant positive correlation between dietary riboflavin intake with energy intake (r=0.581, p<0.001) and protein intake (r=0.749, p<0.001). Riboflavin excretion was found to have significant positive correlation with riboflavin, protein, and energy intakes. A negative correlation between riboflavin excretion and EGRAC was also observed (r=−0.305, p<0.05). The riboflavin status of most of the subjects (90%) of the study appears to have been adequate as assessed by dietary intakes, urinary excretions, and EGRAC values.