Systematic review and meta-analysis approach on vitamin A fortified foods and its effect on retinol concentration in under 10 year children.

OBJECTIVE: To carry out a systematic review and meta-analysis of the trials to identify as well as quantify the effect of vitamin A fortified food on serum vitamin A concentration among children under 10 year. STUDY DESIGN: All the relevant studies has been retrieved by MEDLINE, PubMed, Embase, ProQuest and the Cochrane Library and secondary referencing. A random effects model was applied to compute the pooled effect size of effect of serum retinol. Meta regression was performed to detect the sources of heterogeneity and moderator variables on the study effect. We included all the relevant randomized control trials. These studies were assessed for inclusion and validity, with independent duplication. RESULTS: Out of 648 published studies, fourteen were included and evaluated. These studies were covering 6153 children and the duration of feeding for the fortified foods ranged between 3 and 12 months. A pooled effect size of vitamin A fortification on retinol in children was estimated (N 6153; Standard Mean Difference = 0.47; 95% CI 0.16, 0.78). However, there was evidence of substantial heterogeneity of estimate on effect (I2 = 97%, τ2(tau-squared) = 0.55, p < 0.01). CONCLUSION: This study suggests that consumption of Vitamin A fortified foods results in increased concentration of retinol and thereby results in reduction of Vitamin A deficiency among the children.