RIBOFLAVIN STATUS OF THE ELDERLY - DIETARY-INTAKE AND FAD-STIMULATINGEFFECT ON ERYTHROCYTE GLUTATHIONE-REDUCTASE COEFFICIENTS

Objective: The present study was undertaken to investigate the relatio nship between riboflavin intake and its biochemical status in elderly subjects (greater than or equal to 65 years). Subjects: Thirty males a nd 30 females were randomly selected from a larger sample of free-livi ng elderly residents of Edmonton, Canada. Subjects were contacted thro ugh a seniors' service organization and the Medical Officer of Health. Any subject using vitamin supplements or alcohol other than the occas ional drink was excluded from the study. Design: Dietary intake was es timated using a 3-nonconsecutive-day food record. Biochemical status w as assessed by measuring the erythrocyte glutathione reductase activit y coefficient (EGRAC), which is a functional test indicative of metabo lic availability of riboflavin. Results: Average daily riboflavin inta ke of the study population was above the recommended requirement (0.5 mg/1000 kcal). According to the frequently used criterion that an EGRA C value greater than or equal to 1.20 is indicative of inadequate ribo flavin status, 23% of the males and 7% of the females were classified as being deficient in the vitamin. However, based on the recently sugg ested normal values (1.30-1.4) for EGRAC, it appeared that all male su bjects but one had adequate riboflavin status. Conclusion: The criteri a used for EGRAC values may affect the interpretation of riboflavin st atus. It is therefore important that guidelines for EGRAC are standard ized for more reliable interpretations. Sponsorship: Kellogg Canada, I nc. Descriptors: elderly, erythrocyte glutathione reductase activity, riboflavin intake, riboflavin status