Does Folic Acid Supplementation Affect Body Weight or Body Mass Index? A Systematic Review and Meta-analysis of a Randomized Controlled Trial

Background & Aims: Folic acid is a widely used supplement with numerous purported health benefits. The purpose of this study was to evaluate the effect of folic acid on body weight (BW) and body mass index (BMI). Methods: This systematic review and meta-analysis of 11 randomized controlled trials (RCTs) evaluated the effects of folic acid supplementation BW or BMI in 514 participants. A systematic search, current as of March 2021, was performed in PubMed/Medline, Scopus, Web of Science, and Embase using relevant keywords to identify eligible studies. A fixed-effects model was used to estimate the weighted mean difference (WMD) and 95% confidence intervals (CIs). Results: 11 RCTs were included in this meta-analysis. The pooled analysis revealed that folic acid supplementation did not affect BW (WMD: 0.16 kg; 95% CI: -0.77 to 1.10; p = 0.727, I²= 0.0%, p = 1.00) and BMI (WMD: 0.05 kg/m²; 95% CI: -0.08 to 0.19; p = 0.447, I²= 0.0%, p = 0.666). Conclusion: Folic acid supplementation did not significantly impact body weight or BMI. Future large-scale RCTs, on various dosages and durations of intervention are needed to elucidate the effects more clearly.