Effect of zinc supplementation on growth of preterm infants

Abstract

Background and objectives: Nutritional deficits are almost universal in low-birth weight babies. This study aimed to show the effect of zinc supplementation on growth and certain hematological parameters in preterm infants. Methods: The current case-control study was carried out on 80 healthy preterm infants below 37 weeks of age divided into two groups. The first group was a zinc-supplemented group fed with breast milk exclusively and supplemented with zinc (2 mg/kg/day) since the first day of life. The second group was a non-zinc-supplemented group fed with breast milk exclusively (without zinc supplementation). Both groups were followed up at the age of 4 months for monitoring growth and determining serum zinc and hemoglobin levels. Results: With the beginning of the study; there was no significant statistical difference between the zinc supplemented & non zinc supplemented groups in weight (2.4±0.2 kg vs 2.5±0.4kg), length (45.0±1.6 cm vs 45.2±1.5 cm) and occipitofrontal circumference (31.5±1.2 cm vs 31.5±1.1cm) respectively, but there was statistical significant difference at 4 months follow up with regard to weight (6.2±0.3 kg vs 6.0±0.2 kg) and length (63.2±2.1 cm vs 61.1±2.0 cm). Also, there was a highly significant increase in serum hemoglobin levels (11.7±1.6 gm/dl vs 10.6±1.5 gm/dl) and serum zinc level (101.2±8.1 µg/dl vs 84.1±7.0 µg/dl) in the zinc-supplemented group compared to the non-zinc-supplemented group at 4 months follow up. Conclusion: Zinc supplementation was found to be effective to enhance the growth as well as increasing serum zinc and hemoglobin levels in early months of life of preterm infants.