Riboflavin Requirement of Healthy Elderly Humans and Its Relationship to Macronutrient Composition of the Diet ,

Abstract

The riboflavin requirements of two groups of riboflavin-deficient, but otherwise healthy, Guatemalan elderly persons over the age of 60 y were studied by varying the fat:carbohydrate ratio in two diets. The first group consumed a diet similar in macronutrient content to a Western-type diet with low carbohydrate and high fat; the second group consumed a typical Guatemalan diet with high carbohydrate and low fat. Energy and protein intakes of both groups were similar. Riboflavin status was monitored by weekly measurements of erythrocyte glutathione reductase activity coefficient (EGRAC) and urinary riboflavin excretion. Increasing increments of riboflavin were added to the subjects' diets until their status was normalized, as indicated by EGRAC of < 1.34 and a sharp increase in urinary riboflavin excretion. Using the EGRAC method, the mean value of riboflavin intake at which the subjects' EGRAC reached the limit of normality was 1.37 +/- 0.03 mg/d in the first phase and 1.29 +/- 0.03 mg/d in the second phase. The sharp increase in urinary excretion occurred at riboflavin intakes of 1.13 and 1.03 mg/d for Groups 1 and 2, respectively. Thus, the differences between the two groups suggest that diets with a lower fat:carbohydrate ratio can decrease the dietary need for riboflavin. The dietary requirement of riboflavin, as estimated by the more reliable urinary excretion method, was 1.1-1.3 mg/d for those consuming the Western-type diet, which is similar to values found over 40 y ago in young adults. We conclude that the dietary requirements of riboflavin in the elderly do not differ from those of young adults.

Dietary Reference Values for riboflavin

“…However, older subjects with urinary riboflavin excretion < 10 μg/g creatinine (and EGRAC > 2) did not show clinical signs of riboflavin deficiency either before or during their participation to the study by Boisvert et al. () (Sections 2.4.1 and 2.4.2).…”

“…The WHO/FAO reported on studies on riboflavin status measured by EGRAC (Belko et al., , ; Bates et al., ; Kuizon, ), on a daily intake of 1.7 mg/day that was largely excreted in the urine (Roughead and McCormick, ), and noted that riboflavin tissue saturation occurred at intake above 1.1 mg/day. Two studies undertaken in older adults were cited (Alexander et al., ; Boisvert et al., ), but no specific value was set for this population.…”

“…The Council set different PRIs for men and women on the basis of different energy intakes (Bates et al., ; Zempleni et al., ). For older adults (over 51 years old), it was considered that data on urinary excretion studies and EGRAC did not suggest the setting of different PRIs from those determined for younger adults (Bates et al., ; Lowik et al., ; Boisvert et al., ; Bates, ).…”

The prevalence and risk factors for age-related macular degeneration in rural–urban India, Sankara Nethralaya Rural–Urban Age-related Macular degeneration study, Report No. 1

“…Boisvert et al recently studied riboflavin-depleted older persons and gradually repleted them with increasing amounts of dietary riboflavin (242). The slope of urinary riboflavin excretion rose sharply when dietary intake reached 1.1 mg per day, which is the identical level at which the slope of the riboflavin-excretion curve changed in a classic study of younger adults (243).…”

Riboflavin Status in Acutely Ill Patients and Response to Dietary Supplements

“…We found no correlation between EGRAC and either total energy or dietary intakes of riboflavin, tissue inflammation, previous illness, medications, hemoglobin, or iron status. 12,13 There were no differences in dietary intakes between supplement and placebo groups, and drinks were well tolerated with no major side effects.…”