Marginal selenium status in northern Tasmania

Abstract

Se plays many important roles in humans. Marginal Se status has been associated with adverse health effects including an increased risk of chronic disease such as cancer. There are few Australian data, but the population of Tasmania, Australia, is potentially at risk of marginal Se status. A cross-sectional study of 498 men and women aged 25-84 years was undertaken to assess the Se status of the northern Tasmanian population. Se status was assessed using dietary estimates and measures of serum Se and glutathione peroxidase (GPx). Mean Se intakes were 77·4 (sd 31·3) and 65·1 (sd 23·7) μg/d for men and women, respectively; 27 % of the subjects consumed less than the Australian/New Zealand estimated average requirement. Mean serum Se concentration was 89·1 (sd 15·1) μg/l; 83 % of the study subjects had serum Se concentrations below 100 μg/l and 60 % had serum Se concentration below 90 μg/l, suggesting that Se status in many subjects was inadequate for maximal GPx activity. This was supported by the positive association between serum Se and serum GPx (P < 0·001), indicating that enzyme activity was limited by Se concentrations. The lowest mean serum Se concentrations were observed in the oldest age ranges; however, the prevalence of marginal Se status was similar across age ranges and did not appear to be influenced by sex or socio-economic status. The prevalence of marginal Se status was high in all sex and age subgroups, suggesting that the northern Tasmanian population could benefit from increasing Se intakes.