Long-term vitamin status and dietary intake of healthy elderly subjects. 1. Riboflavin.
1. Long-term clinical and biochemical riboflavin status and dietary intake of riboflavin were monitored for 18 months in a group of twenty-three relatively-healthy elderly subjects living at home in the north of England. 2. Both dietary intake and biochemical status, as measured by the activation coefficient (stimulated:basal activity) of NAD(P)H2:glutathione oxidoreductase (EC 1.6.4.2), remained fairly constant for each individual and for most subjects the usual intake and biochemical status were characterized quite accurately by a single week's intake dietary record and a single measurement of the activation coefficient. 3. The expected relationship between biochemical status and dietary intake was present, but not strongly evident. There was a significant within-subject correlation between alpha values and the immediately preceding dietary intake; however the between-subject correlation between alpha values and dietary intake approached zero if the two subjects receiving long-term riboflavin supplements were omitted. Over the limited range of intakes observed in unsupplemented subjects, non-dietary factors evidently obscure the relationship. 4. Although eight subjects had average values above 1.2 for the activation coefficient, no excessively high values were observed, and no subject showed any clear-cut clinical deficiency symptoms.
D000368:Aged; D004032:Diet; D004912:Erythrocytes / Q000201:enzymology; D005260:Female; D005980:Glutathione Reductase / Q000097:blood; D006801:Humans; D008297:Male; D009747:Nutritional Physiological Phenomena; D012256:Riboflavin / Q000378:metabolism
D005980:Glutathione Reductase; D012256:Riboflavin