Effects of dietary nucleotide supplementation on growth in infants: a meta-analysis of randomized controlled trials.

Abstract

Dietary nucleotides are thought to be conditionally essential nutrients in infancy. However, studies have reported inconsistent findings regarding the association between nucleotide supplementation and infant physical growth. We conducted this meta-analysis to examine the efficacy of nucleotide supplementation of infant formula in promoting early infant growth. Randomized controlled trials that evaluated the association between nucleotide supplementation and infant growth through June 2017 were included. Study quality was assessed using the Cochrane Collaboration's Risk of Bias tool. Standardized mean differences (SMD) with 95% confidence intervals (CIs) were calculated. Heterogeneity was assessed using Q and I2 tests. Nucleotide supplementation significantly increased the rate of weight gain (SMD 0.26; 95% CI 0.06-0.47), but had no effect on weight (SMD -0.16; 95% CI -0.55-0.23), weight Z score (SMD, -0.42; 95% CI -1.64-0.81), length (SMD 0.01; 95% CI -0.18-0.21) and length Z score (SMD 0.15; 95% CI -0.10-0.40). Occipitofrontal head circumference (OFC) at 7-8 weeks (SMD 0.30; 95% CI 0.10-0.50) and the rate of OFC gain (SMD 0.34; 95% CI 0.09-0.58) were significantly improved with nucleotide supplementation, whereas, 16- and 20-week OFC values did not differ. Our meta-analysis indicated that nucleotide supplementation can increase the rate of weight gain, OFC and rate of OFC gain; however, we cannot conclude that it affects weight, weight Z score, length or length Z score. Large-scale randomized controlled trials of long-term nucleotide supplementation are needed to reach definitive conclusions.