Biochemical evaluation of riboflavin and vitamin B6 status of institutionalized and non-institutionalized elderly in Central Kentucky.

A study was conducted to assess the nutritional status of riboflavin and vitamin B6 of the elderly in Central Kentucky. Elderly subjects aged 60 to 95, including 42 men and 77 women, were randomly selected: 41 from six nursing homes and 78 from private residences. Blood and urine samples were collected for analysis. Riboflavin and vitamin B6 status were assessed by using glutathione reductase activation coefficient and glutamic-pyruvic transaminase activation coefficient, respectively. Glutathione reductase activation coefficients ranged from 0.88 to 1.89 with a mean +/- SD of 1.23 +/- 0.22, and were not significantly correlated with the urinary excretion of riboflavin. Glutamic-pyruvic transaminase activation coefficients ranged from 0.86 to 1.50 with a mean +/- SD of 1.16 +/- 0.14, and were negatively correlated with urinary excretion of 4-pyridoxic acid. Riboflavin deficiency was found in 34.2 percent of the institutionalized and 27.7 percent of the non-institutionalized subjects, while vitamin B6 deficiency was found in 56.6 percent of the institutionalized and 43.5 percent of the non-institutionalized subjects studied. The institutionalized elderly showed significantly poorer riboflavin status (P less than 0.01) and vitamin B6 status (P less than 0.05) than the non-institutionalized elderly. Aging was associated with a significant decline in both riboflavin (P less than 0.01) and vitamin B6 status (P less than 0.05).