Selenium status in adults and children in Lusaka, Zambia

Background: Selenium (Se) is a trace element found in many foodstuffs and critical for antioxidant and immune functions. Widespread Se deficiency has been noted in populations of some sub-Saharan African countries including Ethiopia and Malawi. As a first step towards developing a fuller understanding of problems with the availability of Se in the diet in Lusaka province, Zambia, we measured plasma Se in adults and children in this geographic area. Methods: Total plasma Se was measured using inductively coupled plasma optical emission spectrometry (ICPOES) in several groups of adults recruited to various pre-existing studies, including those of high and low socioeconomic status (SES) and pregnant women, and children with a range of nutritional states (healthy, stunted or wasted).Results: A total of 660 plasma samples from 391 adults and 269 children were included. Adults had a median plasma Se concentration of 0.27 mu mol/l (IQR 0.14-0.43). Concentrations consistent with deficiency (<0.63 mu mol/ l) were found in 83% of adults. Low SES was associated with low plasma Se among adults, [OR 0.1; 95% CI 0.1-0.3, p < 0.0001]. Among the children, 24% had plasma Se less than 0.41 mu mol/l. There was a statistically significant positive correlation between plasma Se and age among children, Spearman's rho 0.47, p < 0.0001.Conclusions: These data suggest that Se deficiency is widespread in Lusaka province and could in part be related to socio-economic status. Supplementation or agronomic biofortification may therefore be needed.

Automated summary

This study found widespread selenium deficiency in Lusaka province, Zambia, with low selenium concentrations in both adults and children. Low socioeconomic status was associated with selenium deficiency, and there was a positive correlation between children's selenium concentrations and age. Supplementation or agronomic biofortification may be needed to address the selenium deficiency.