Zinc deficiency among the elderly attending a care centre in Sharpeville, South Africa

The elderly are particularly prone to zinc deficiency because of nutritional and physiological vulnerabilities associated with ageing. A low socio-economic status may further increase the risk of zinc deficiency. This cross-sectional descriptive study assessed the zinc status of an elderly sample in the Vaal region, South Africa. The participants were 170 randomly selected elderly people attending a day care centre in Sharpeville. Twenty-four-hour recalls were administered for dietary intake. Weight and height were measured and venous blood samples (n = 67) were drawn to determine biochemical indices. The mean age of the respondents was 71.7 years. The mean +/- SD daily dietary intake for zinc was 11.0 +/- 6.12 mg. Approximately half of the subjects (51.5%) did not reach two-thirds of the recommended dietary allowance for zinc. The mean serum zinc concentration was 61.8 +/- 8.5 mu g dL(-1) (9.4 +/- 1.3 mu mol L-1), with 76.3% of the subjects having zinc values less than the recommended values of 70 mu g dL(-1) (10.7 mu mol L-1). Maize meal was the staple in the diet of approximately half the study population. Although South African maize meal is now fortified with zinc oxide, maize also contains high concentrations of phytate, a known inhibitor of mineral bioavailability. The results of the present study suggested that zinc deficiency existed in these elderly people. Further research is, however, needed to elucidate possible underlying factors so that appropriate intervention can be implemented.