Serum concentration and dietary intake of Zn in healthy institutionalized elderly subjects

We determined the serum concentrations and dietary intake of zinc, as indicators of Zn status, in 44 healthy institutionalized elderly subjects in Granada (Spain) (mean age 81.4 ± 7.9 years). Determination of Zn in serum was carried out by electrothermal atomic absorption spectrophotometry. Serum samples had a mean Zn concentration of 10.49 ± 3.5 μmol/l. No significant differences were found in the serum levels of Zn as regards the sex of the subjects. However, concerning Zn intake, determined by a 7-day weighed food record, a significant statistical difference (P < 0.001) was found between men and women, with mean values of 10.01 ± 1.76 mg/day and 7.33 ± 1.33 mg/day, respectively. Application of regression analysis to the serum concentration of Zn and other nutritional parameters shows a statistically significant correlation (P < 0.05) between serum levels of Zn and the body mass index. The lack of statistical correlation between the serum concentration of zinc and its intake indicates that this index cannot be used as an indicator of zinc status in the elderly.