Redistribution of vitamin A after iron supplementation in Indonesian infants.

Masked supplementation trial in Indonesian infants recruited at about 4 months of age from 6 villages in rural Bogor District, West Java, Indonesia, and followed for 6 months. Active intervention arms were compared with placebo to assess interactions among iron, vitamin A, and zinc status.

Infants received oral micronutrient syrup and/or oil 5 days per week for 6 months. Active regimens were iron 10 mg/d as ferrous sulfate, iron plus zinc 10 mg/d each, zinc 10 mg/d as zinc sulfate, zinc plus beta-carotene 10 mg/d zinc sulfate plus 2.4 mg beta-carotene, or beta-carotene 2.4 mg/d alone; masking used separate syrup and oil bottles.

Iron supplementation worsened vitamin A status by lowering plasma retinol while increasing liver vitamin A stores, consistent with redistribution of retinol from plasma to the liver. After 6 months, plasma retinol was 0.62 ± 0.17 in the iron group and 0.56 ± 0.17 in the iron plus zinc group versus 0.74 ± 0.26 in placebo; hemoglobin and ferritin improved with iron, with ferritin 38.2 (18.0-68.1) and 31.7 (17.4-41.6) versus 15.2 (8.2-28.1). Zinc-containing regimens improved zinc status, with plasma zinc 15.5 (13.8-19.0) to 16.5 (13.7-21.0) versus 14.2 (11.9-15.9) in placebo. Beta-carotene increased plasma beta-carotene in beta-carotene-containing groups but did not significantly improve vitamin A status.

Single rural Indonesian infant cohort limits generalizability. Follow-up was only 6 months, and adverse events were not reported. Several outcomes had incomplete arm-specific data, and the multiarm design leaves some comparisons underpowered for smaller differences.