RESUMO
The investigation concerned 572 children, 6-11 years of age, who were divided into three groups: urban control, rural control and rural study. During the first phase of supplementation, each child received 120 mg of elemental iron (as ferrous sulphate) with 0.50 mg of folic acid daily for 60 school days (five days a week) which resulted in a suboptimal haemoglobin concentration. During the second phase, all groups continued to take iron-folate tablets for 60 school days while the children in the study group also received protein, vitamins and minerals. Final blood examinations showed no significant difference in mean haemoglobin concentrations between the rural study and rural control groups. Only 1.5% of all children had haemoglobin below 12 g/dl. It can therefore be concluded that strict supervision of iron tablet intake and long-term supplementation with iron are essential for optimal haemoglobin response.