Objectives To evaluate whether preterm very low birth weight (VLBW) infants receiving early iron (EI) supplementation (2 mg/kg/day elemental iron) at 2 weeks postnatal age have improved serum ferritin levels compared with late iron (LI) supplementation at 6 weeks postnatal age.

Design Single-blinded parallel-group interventional randomised controlled trial.

Setting Tertiary care centre in southern India.

Interventions Randomised at 2 weeks postnatal age to EI and LI groups and evaluated at 2, 6 and 12 weeks postnatal age.

Outcome The primary outcome was serum ferritin level at 12 weeks, and the secondary outcomes were the incidence of neonatal morbidities, haemoglobin level, anthropometric parameters and blood transfusion requirements.

Results Of the 104 babies randomised, outcomes were analysed in 46 and 47 babies in EI and LI groups, respectively. Serum ferritin level was significantly higher (p<0.001) at 12 weeks (82±5 vs 63±3 ng/mL) in the EI group. Haemoglobin (10.1±0.4 vs 9.2±0.4 g/dL) and mean corpuscular haemoglobin concentration (31±0.5 vs 29.4±0.5 g/dL) were also significantly (p<0.001) higher at 12 weeks in the EI group. There was a significant decrease of ferritin in the LI group and significant increase in ferritin in the EI group at 6 weeks compared with 2 weeks. There were no significant differences in the incidences of neonatal morbidities (necrotising enterocolitis, periventricular leukomalacia, retinopathy of prematurity), anthropometric parameters and blood transfusion requirements between the two groups.

Conclusions EI supplementation in preterm VLBW infants improves serum ferritin and haemoglobin levels.

Trial registration: CTRI/2013/01/003277.