A comprehensive meta-analysis on the association between vitamin C intake and gestational diabetes mellitus: Insights and novel perspectives

Gestational Diabetes Mellitus (GDM) is a significant health concern in pregnant women and their offspring. Although Vitamin C is known to play a role in maintaining normal physiological processes, its relationship with GDM has not been fully elucidated. METHODS: We conducted a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, analyzing data from 15 studies selected from PubMed, Embase, Web of Science, and the Cochrane Library up to May 16, 2023. These studies were selected based on inclusion criteria such as study design, outcome of interest, exposure factor, and data extractability. Quality assessment was performed using the Newcastle-Ottawa Scale. We assessed the heterogeneity between studies and conducted a sensitivity analysis. RESULTS: Data from 10,131 subjects, including 1304 diagnosed GDM cases, were analyzed. The meta-analysis showed that women in the low Vitamin C exposure group had higher odds of developing GDM (odds ratio 2.72, 95% CI:1.24–4.19). There was a greater likelihood of increased GDM risk with lower Vitamin C exposure (standardized mean difference: −0.71, 95% CI [−1.07 −0.36]). Subgroup analysis revealed that both internal and external Vitamin C exposure, along with exposure during the second or third trimester of pregnancy, was associated with higher GDM incidence rates under low Vitamin C exposure. Sensitivity analysis confirmed the robustness of the results, and no significant publication bias was detected. CONCLUSION: Low Vitamin C exposure during pregnancy may increase the risk of GDM. Given these findings, it could be beneficial for pregnant women to increase their intake of Vitamin C-rich foods and to ensure adequate blood Vitamin C levels as a preventive measure against GDM.