Vitamin B12 in Pregnancy and its Relationship with Maternal BMI and Gestational Diabetes Mellitus

Objectives: To determine the levels of vitamin B12 in pregnant women and to explore the relationship of vitamin B12 with maternal BMI and gestational diabetes mellitus.

Methods: This cross-sectional study was conducted at Department of Physiology, UHS, Lahore from February 2019 to March 2020. Ninety pregnant women in early third trimester of pregnancy were selected. Forty-five women had gestational diabetes and forty-five were healthy pregnant women. Serum vitamin B12 and fasting blood glucose (FBG) levels were determined by ELISA and glucose oxidase method respectively. 1st trimester BMI was also recorded. SPSS version 23 was used to analyze the data.

Results: Serum vitamin B12 was significantly lower in GDM group (149.41±13.66) as compared to non-GDM group (357.49±42.07). BMI was significantly higher in GDM group (32.94±2.10) as compared to non-GDM group (23.52±1.83). Significant negative correlation (-0.78**) was observed between 1st trimester BMI and vitamin B12 in late pregnancy. Regression analysis revealed that high BMI was associated with decrease in vitamin B12 and increased risk of gestational diabetes mellitus (3.26***). Moreover, vitamin B12 was partially mediating the relationship between BMI and FBG.

Conclusion: Low vitamin B12 levels have an association with maternal BMI and gestational diabetes mellitus.