Blood selenium and glutathione peroxidase levels and dietary selenium of free-living and institutionalized elderly subjects.

The purpose of this study was to evaluate the selenium status of healthy free-living and institutionalized elderly people. For the 36 free-living elderly dietary selenium intake averaged 94 +/- 44 micrograms Se/day and a positive correlation coefficient was found between dietary selenium and dietary calories (r = 0.46; P less than 0.05), dietary protein (r = 0.60; P less than 0.01), and dietary fat (r = 0.43; P less than 0.05). Diet histories from the institutionalized subjects revealed a strong correlation coefficient between selenium and carbohydrate (r = 0.51; P less than 0.005) and selenium and calories (r = 0.44; P less than 0.05). Mean erythrocyte and plasma selenium levels for the free-living subjects were 0.20 +/- 0.06 micrograms/ml and 0.10 +/- 0.03 micrograms/ml, respectively, while mean erythrocyte glutathione peroxidase (GSH-Px) activity was 27.5 +/- 5.0 units/g protein. For the free-living subjects positive correlation was found between dietary selenium and erythrocyte selenium levels (r = 0.38; P less than 0.05) but no correlation existed between dietary selenium and plasma selenium (r = 0.13; P greater than 0.05) and RBC GSH-Px (r = -0.15; P greater than 0.05). The dietary selenium levels and blood selenium and GSH-Px levels were above the levels found in populations proposed to be at risk for selenium deficiency. Thus, these elderly appear to have adequate selenium status.