Iron-deficiency anemia in children remains one of the most important nutritional problems faced by developing countries. Well-controlled efficacy studies show that intermittent iron supplementation can improve children's iron status as well as the traditional daily schedule. This gives new impetus to controlling child anemia by weekly preventive iron supplementation. The objective of this study is to evaluate the effectiveness of long-term preventive provision of weekly doses of iron sulfate to all children from 6 to 59 months of age, in a child population in which anemia is highly prevalent. Children from both the intervention and control groups were selected from a random cross-sectional sample of the child population of the city of São Paulo, Brazil. Parents in the intervention group were visited in their homes and received nutrition education plus a solution of iron sulfate with the request to give it to their children once a week until a follow-up visit occurred in approximately six months. Parents in the control group received only nutrition education. The effect of the intervention was assessed by changes in hemoglobin concentration and the prevalence of anemia. Comparisons between the two groups were made based on an intention-to-treat approach, and all estimates were adjusted for initial hemoglobin concentration, initial age, total duration of follow-up and family income. The average hemoglobin gain due to the intervention was 4.0 g/l, with a fall of more than 50% in the prevalence of anemia among the children. The intervention was particularly effective in preventing declines in hemoglobin concentration during the first two years of life. This study demonstrates that long-term preventive weekly iron supplementation for preschool children significantly reduces the risk of anemia under conditions similar to those possible in routine public health programs.
Anemia; Iron-deficiency; Iron weekly supplementation; Dietary supplements; Children; Nutritional intervention
