Iron Supplements Reduce the Risk of Iron Deficiency Anemia in Marginally Low Birth Weight Infants

Abstract

OBJECTIVE: Low birth weight infants are at risk for iron deficiency (ID). Most LBW infants have marginally low birth weight (MLBW, 2000-2500 g) and it is not known whether they benefit from iron supplements. The objective of this trial was to study the effects of iron supplementation in MLBW infants. METHOD: In a randomized controlled trial, we assigned 285 healthy, MLBW infants to receive iron supplements at a dose of 0 (placebo), 1, or 2 mg/kg per day between 6 weeks and 6 months of age. Hemoglobin levels, ferritin levels, transferrin saturation, mean cell volume, and transferrin receptor levels were analyzed at 6 months. Growth and morbidity were monitored. RESULTS: Iron supplementation resulted in significant dose-dependent effects on hemoglobin and all iron status indicators at 6 months. The prevalence of ID at 6 months was 36% in the placebo group, 8.2% in the 1 mg/kg per day group, and 3.8% in the 2 mg/kg per day group (P<.001). The prevalence rates of ID anemia (IDA) were 9.9%, 2.7%, and 0%, respectively (P=.004). Among infants who were exclusively breastfed at 6 weeks, the prevalence of IDA was 18% in the placebo group. There were no significant differences between groups in growth or morbidity. CONCLUSIONS: MLBW infants have relatively high risks of ID and IDA, especially if they are breastfed. Iron supplementation at 2 mg/kg per day from 6 weeks to 6 months reduces this risk effectively, with no short-term adverse effects on morbidity or growth.