A community-based randomized controlled trial of iron and zinc supplementation in Indonesian infants: interactions between iron and zinc

A community-based randomized controlled trial of iron and zinc supplementation in Indonesian infants: interactions between iron and zinc

Combined supplementation with iron and zinc during infancy may be effective in preventing deficiencies of these micronutrients, but knowledge of their potential interactions when given together is insufficient. The goal of the research study in Indonesia was to compare the effect in infants of combined supplementation with iron and zinc and of supplementation with single micronutrients on iron and zinc status.

680 Indonesian infants were randomly assigned to daily supplementation with 10 mg iron, 10 mg zinc, 10 mg iron and 10 mg zinc, or a placebo from 6 to 12 months of age. Venous blood samples were collected at the start and end of the study. 549 infants completed the supplementation and had both baseline and follow-up blood samples available for analysis.

Baseline prevalences of anemia, iron deficiency anemia, and low serum zinc were 41%, 8%, and 78%, respectively. After supplementation, the iron group had higher hemoglobin and serum ferritin values than did the iron and zinc group, indicating an effect of zinc on iron absorption. The zinc group had higher serum zinc than did the placebo group. There was a dose effect on serum ferritin in the iron and iron and zinc groups, but at different levels. There was a significant dose effect on serum zinc in the zinc group, whereas no dose effect was found in the iron and zinc group.

Supplementation with iron and zinc was less efficacious than were single supplements in improving iron and zinc status, with evidence of an interaction between iron and zinc when the combined supplement was given.

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