Role of Maternal Serum Vitamin B12 Concentration with Risk of Developing Gestational Diabetes Mellitus

Background: Gestational diabetes mellitus (GDM) is one of the most common complications in pregnant women. Vitamin B12 serves in synthesis of methionine from homocysteine. Low vitamin B12 inhibits DNA synthesis and elevates homocysteine. Elevated homocysteine level linked with insulin resistance that is associated with GDM. Various researchers suggested an association of serum vitamin B12 concentration with GDM. Estimation of serum vitamin B12 may be helpful in management of GDM. Objective: To observe the association of vitamin B12 concentration with risk of developing GDM. Methods: This cross-sectional study was carried out at the Department of Laboratory Medicine, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh between March 2021 and February 2022. A total of 86 women were enrolled; of them 43 were GDM women selected as cases and 43 were normal pregnant women taken as control group. Their demographic profile, relevant medical history with clinical examination findings were recorded. Serum vitamin B12 concentrations of the study population were estimated following standard procedure. Results: The mean serum vitamin B12 concentration was found significantly low in GDM women (158.7±91.8 pmol/L versus 264.5±100.9 pmol/L, p= 0.001). Pearson’s correlation coefficient test between serum vitamin B12 concentration with fasting plasma glucose level, plasma glucose level 1 hours after 75 gm glucose and plasma glucose level 2 hours after 75 gm glucose showed a significantly negative correlation (r= -0.432, p= 0.004; r= -0.519, p<0.001 and r= -0.687, p<0.001). In multivariate logistic regression analysis, the odd ratio of vitamin B12 concentration with GDM was 1.997 (95% CI; p= 0.042). Conclusion: Serum vitamin B12 concentration is significantly low in GDM women, which is negatively correlated with plasma glucose levels among GDM women. Serum vitamin B12 concentration may be used as a predictive tool to identify risk of developing GDM.