Efficacy of vitamin C supplementation during pregnancy in the prevention of preterm birth: a systematic review and meta-analysis

source extracted confidence: high 2026-04-09
#humans #pregnancy #premature-birth #female #ascorbic-acid

Efficacy of vitamin C supplementation during pregnancy in the prevention of preterm birth: a systematic review and meta-analysis

Pereira et al., 2025 | Rev Bras Ginecol Obstet | Meta Analysis

Citation

Pereira Ana Gabriela Alves, Molino Gabriela Oliveira Gonçalves, ... da Silva Pedro Henrique Costa Matos. Efficacy of vitamin C supplementation during pregnancy in the prevention of preterm birth: a systematic review and meta-analysis. Rev Bras Ginecol Obstet. 2025;47. doi:10.61622/rbgo/2025rbgo1

Abstract

OBJECTIVE: Preterm birth is a leading global cause of neonatal mortality and morbidity, with oxidative stress playing a role in its pathogenesis. Vitamin C, a powerful antioxidant, may help reduce this risk. This study assessed the effectiveness of vitamin C supplementation, both alone and with vitamin E, in preventing preterm birth compared to a placebo. DATA SOURCE: Databases were systematically searched in PubMed, Cochrane and Embase in December 2023 and updated in May 2024. STUDY SELECTION: Included RCTs evaluated vitamin C's effect on preterm birth and related neonatal outcomes. DATA COLLECT: Statistical analyses used a random-effects model for pooled risk ratios (RR) and 95% confidence intervals (CI). Heterogeneity was assessed with the I² statistic. DATA SYNTHESIS: Seventeen RCTs (21,567 patients) were analyzed. Vitamin C supplementation showed no significant difference compared to placebo for preterm birth (RR 1.04; 95% CI 0.96, 1.14). No significant differences were observed for neonatal death (RR 0.77; 95% CI 0.55, 1.08), NICU admission (RR 1.03; 95% CI 0.95, 1.13), preterm PROM (RR 1.04; 95% CI 0.63, 1.71), or birth weight (MD 52.41; 95% CI -19.65, 124.47). A slight decrease in gestational age was observed (MD 0.26; 95% CI -0.02, 0.55). CONCLUSION: Vitamin C supplementation alone or in combination with vitamin E does not significantly prevent preterm birth or improve related neonatal outcomes.

Key Findings

Vitamin C supplementation alone or in combination with vitamin E does not significantly prevent preterm birth or improve related neonatal outcomes.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 21567
Age Range See abstract
Condition stress

MeSH Terms

  • Humans
  • Pregnancy
  • Premature Birth
  • Female
  • Ascorbic Acid
  • Dietary Supplements
  • Infant, Newborn
  • Randomized Controlled Trials as Topic
  • Antioxidants
  • Vitamin E

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Journal Article, Systematic Review, Meta-Analysis
  • Vertical: vitamin-c

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09