Nutritional anaemia in 11-year-old schoolchildren in the western Cape.

A nutritional anaemia survey was carried out on 610 11-year-old coloured, black and white schoolchildren in urban and rural communities in the western Cape. The mean (+/- 1 SD) haemoglobin concentration was 13.0 +/- 1.2 g/dl. The coloured and black subgroups considered together had a significantly lower mean haemoglobin concentration than the white subgroup (12.8 +/- 1.2 g/dl v. 13.4 +/- 1.0 g/dl) (F = 37.47; P less than 0.0001). The urban population as a whole had a significantly lower geometric mean (1 SD range) serum ferritin concentration than the rural population (25.6 (13.5-48.6) micrograms/l v. 34.1 (21.3-54.6) micrograms/l) (F = 42.94; P less than 0.0001). The lowest geometric mean serum ferritin values were found in the urban coloured (23.1 (11.5-46.4) micrograms/l) and urban black schoolchildren (23.7 (13.2-42.6) micrograms/l), with figures of less than 12 micrograms/l in 11.7% and 12.5% respectively. Although 28% of the children had red cell folate values below the recommended lower limit of normal (175 ng/ml), probability plot analysis of the data suggested that folate deficiency was not a major problem in the study population. The calculated daily iron and folate intakes were below the age-related recommended dietary allowance (RDA) in all the subgroups, yet anaemia was relatively uncommon. These findings suggest that the RDA values are too high. Overall the prevalence of nutritional anaemia was low and only the urban coloured subgroup showed significant second populations with low haemoglobin and serum ferritin measurements.