Selenium and zinc status are suboptimal in a sample of older New Zealand women in a community-based study

The importance of selenium and zinc in the immune functioning of the aged i s widely recognized. Seniors in New Zealand are at particularly high risk o f low selenium status because of the low selenium soil environment. The zin c status of the New Zealand elderly has never been assessed. In this cross- sectional study, the biochemical selenium, zinc and lipid levels, physical functional capacity and dietary intakes of 103 randomly selected free-livin g New Zealand women (mean age +/- SD, 75 +/- 3 y) were assessed. Among nonu sers of selenium supplements (n = 80), 80% [95% confidence interval (Cl): 7 0; 88%] had plasma selenium levels (0.85 +/- 0.23 mu mol/L) below 1.00 mu m ol/L [similar to 10% below mean plasma selenium necessary for full expressi on of glutathione peroxidase (GPx) activity in New Zealand subjects]. Plasm a selenium was strongly correlated with GPx: r = 0.56; P < 0.0001. For nonu sers of zinc supplements (n = 88), serum zinc concentrations were 12.4 +/- 1.4 mu mol/L, with 12% (95% CI: 6; 21%) having levels below the cut-off val ue (10.7 mu mol/L). Estimated mean daily selenium and zinc intakes were 34 +/- 10 mug and 8.7 +/- 2.0 mg, respectively. Subjects in the highest tertil e of a functional capacity index had higher biochemical zinc and selenium v alues than those in the lowest tertile (P < 0.05). The correlation between plasma selenium and GPx indicates that selenium intake in these women is st ill insufficient for full expression of GPx activity. Lower serum zinc leve ls also appear to be prevalent. Because a suboptimal trace element status m ay be more common among those with a poor physical functioning, promotion o f the consumption of nutrient dense foods or supplements to improve seleniu m and zinc status of elderly women in New Zealand may be beneficial.