Riboflavin status of the elderly: dietary intake and FAD-stimulating effect on erythrocyte glutathione reductase coefficients.
OBJECTIVE
The present study was undertaken to investigate the relationship between riboflavin intake and its biochemical status in elderly subjects (> or = 65 years).


METHODS
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Toh
S Y
SY
Department of Food Science and Nutrition, University of Alberta, Edmonton, Canada.
Thompson
G W
GW
Basu
T K
TK
D000368:Aged; D002149:Energy Intake; D004789:Enzyme Activation; D004912:Erythrocytes / Q000201:enzymology*; D005260:Female; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism*; D005980:Glutathione Reductase / Q000097:blood*; D006801:Humans; D008297:Male; D012256:Riboflavin / Q000378:metabolism*; D013997:Time Factors
D005182:Flavin-Adenine Dinucleotide; D005980:Glutathione Reductase; D012256:Riboflavin