Iron Supplementation at 1 mg/kg/Day for Exclusively Breastfed Full-Term Infants: A Meta-Analysis.

Aim: The aim for the study is to evaluate the effects of 1 mg/kg/day iron supplementation on hematologic and growth parameters in exclusively breastfed full-term infants. Methods: We conducted a meta-analysis of seven RCTs (n = 1114) comparing iron supplementation with placebo/no intervention. Primary outcomes included hemoglobin (Hb), serum ferritin (SF), mean corpuscular volume (MCV), height, and weight. Data were analyzed using RevMan 5.4. Results: Iron supplementation from 4 to 6 months significantly increased Hb (MD = 6.29 g/L, p = 0.01), but effects diminished with longer duration (MD = 2.00 g/L, p = 0.08). For SF, no significant difference was found at 6 months, but supplementation significantly increased SF at 12 months (MD = 5.95 μg/L, p = 0.04). No significant differences were found in MCV, height, or weight. Subgroup variations were noted by formulation and region. Conclusion: While short-term iron supplementation improves iron status, the lack of sustained benefits suggests individualized approaches may be preferable to universal supplementation in well-nourished populations.