A randomized double-blind controlled trial comparing two regimens of vitamin D supplementation in preterm neonates

Objective:to compare the efficacy of 400 vs 1000 iu oral vitamin d supplementation in preterm neonates of 27 to 34 weeks gestation.methods:this double-blind randomized controlled trial allocated preterm babies to receive either 400 or 1000 iu of vitamin d3 (n=60 in each group). primary outcome was prevalence of vitamin d insufficiency (serum vitamin d levels<20 ng ml−1) at 40 weeks of corrected gestational age (cga).results:at term cga vitamin d insufficiency was significantly lower in the 1000 iu group than in the 400 iu group (2% vs 64.6%, p⩽0.001). although elevated vitamin d levels were seen in 9.8% of babies on 1000 iu per day, this was not associated with clinical or biochemical evidence of toxicity.conclusion:supplementing preterm babies with 1000 iu of vitamin d3 daily decreases the prevalence of vitamin d insufficiency at term cga. excess levels of vitamin d may occur at this dose in some babies.