Riboflavin requirements of Filipino children and non-pregnant, pregnant and lactating women: Studied by the erthrocyte glutathione reductase activation test.

Riboflavin requirements were studied in six non-pregnant, 12 pregnant, 11 lactating women, 20 children aged 4-6 years and 14 children aged 10-12 years. All subjects initially were riboflavin-deficient with erythrocyte glutathione reductase activation coefficient (EGR-AC) of >=1.3, confined in a metabolic ward and repleted with increasing doses of riboflavin during four 10 or 8 day feeding periods. The repletion diet simulated the usual basal diet of the subjects but were modified to contain adequate energy and protein in the pregnant group. Minimum riboflavin requirements determined by regression analysis as intakes required to obtain an EGR-AC value of < 1.3 were: 0.72 ± 0.09 (non-pregnant); 1.36 ± 0.37 (pregnant); 1.31 ± 0.16 (lactating); 0.58 ± 0.10 (children 4-6 years), and 0.70 ± 0.18 mg/d (children 10-12 years). Riboflavin requirements in mg/d, mg/1000 kcal, mg/g protein or mg/kg metabolic body size for the groups varied. Because of the large variability, the use of a single value relating riboflavin requirement to either energy,protein requirements or metabolic body size to calculate requirements for different age groups or gender is deemed inappropriate. It is recommended that riboflavin requirements be expressed in mg/d as determined experimentally for different population groups. Estimated recommended dietary allowances for the groups studied, obtained by adding 30% to the mean minimum riboflavin requirement, are presented.