[Prevalence of iron-deficiency anemia in schoolchildren and adolescents, Medellín, Colombia, 1999].

OBJECTIVE

This research had two objectives: (1) to determine the prevalence of iron-deficiency anemia and describe iron consumption in the diet of schoolchildren and adolescents enrolled in public and private schools of the urban area of the city of Medellín, Colombia, in the 1999-2000 school year and (2) to explore the associations that age group, sex, socioeconomic class, and intestinal parasitism show with iron-deficiency anemia and iron deficiency.

METHODS

A cross-sectional study was carried out among 960 students from 6 to 18 years old who were selected by simple random sampling after stratified multistage sampling and clustering in public and private schools in districts of Medellín. Body iron content was evaluated by determining ferritin and hemoglobin levels, average corpuscular volume, and amplitude of the erythrocyte distribution; the presence of intestinal parasites was evaluated through stool analysis; nutritional status was evaluated by means of anthropometric measurements; and consumption of iron and vitamin C was evaluated using a semiquantitative questionnaire on food intake. In order to define the cases of iron-deficiency anemia and of iron deficiency we used the standard definitions of the World Health Organization, based on ferritin and hemoglobin values. We used nonparametric tests, with a significance level of 0.05, to examine the associations between age group, sex, socioeconomic class, and the presence of intestinal parasites on the one hand and the presence of anemia on the other hand.

RESULTS

The prevalence of iron deficiency was 4.9%, and the prevalence of iron-deficiency anemia was 0.6%. The prevalence of both was higher among adolescent women (P < 0.05) than in the rest of the sample studied. No significant association was found between the presence of intestinal parasites and the presence of anemia. The average daily consumption of iron (+/- standard deviation) was 5.5 mg (+/- 2.3 mg) (32% +/- 15% of the recommended dietary intake for the studied age group); the average contribution of serum iron in the diet was 0.7 mg (+/- 0.7 mg). Comparing the children who did and who did not have anemia, there were no significant differences in iron consumption and the type of iron consumed. The anthropometric parameter that showed the greatest association with the presence of anemia was height for age.

CONCLUSIONS

The prevalences of iron deficiency and of iron-deficiency anemia found in the population studied were low, according to the parameters for hemoglobin and ferritin as defined by the World Health Organization as being normal for these population groups. The low prevalence of blood-sucking parasites, adequate consumption of vitamin C, and the refined mechanisms with which the body regulates iron homeostasis may have contributed to these results. Adequate iron content in the diet of adolescents should be maintained, and education campaigns should be implemented to help prevent iron deficiency in this population group.