Riboflavin status of the elderly: dietary intake and FAD-stimulating effect on erythrocyte glutathione reductase coefficients

• Published in: European journal of clinical nutrition Vol. 48; no. 9; p. 654
• Main Authors: Toh, S Y, Thompson, G W, Basu, T K
• Format: Journal Article
• Language: English
• Published: England 01.09.1994
• Subjects: Aged; Energy Intake; Enzyme Activation; Erythrocytes - enzymology; Female; Flavin-Adenine Dinucleotide - metabolism; Glutathione Reductase - blood; Humans; Male; Riboflavin - metabolism; Time Factors
• ISSN: 0954-3007

The present study was undertaken to investigate the relationship between riboflavin intake and its biochemical status in elderly subjects (> or = 65 years). Thirty males and 30 females were randomly selected from a larger sample of free-living elderly residents of Edmonton, Canada. Subjects were contacted through a seniors' service organization and the Medical Officer of Health. Any subject using vitamin supplements or alcohol other than the occasional drink was excluded from the study. Dietary intake was estimated using a 3-nonconsecutive-day food record. Biochemical status was assessed by measuring the erythrocyte glutathione reductase activity coefficient (EGRAC), which is a functional test indicative of metabolic availability of riboflavin. Average daily riboflavin intake of the study population was above the recommended requirement (0.5 mg/1000 kcal). According to the frequently used criterion that an EGRAC value > or = 1.20 is indicative of inadequate riboflavin status, 23% of the males and 7% of the females were classified as being deficient in the vitamin. However, based on the recently suggested normal values (1.30-1.4) for EGRAC, it appeared that all male subjects but one had adequate riboflavin status. The criteria used for EGRAC values may affect the interpretation of riboflavin status. It is therefore important that guidelines for EGRAC are standardized for more reliable interpretations.