Endocrine Abstracts

Objective/Design: Gestational diabetes mellitus (GDM) has been associated with serious complications for both the pregnant woman and the newborn. Vitamin B12 is implicated in some important metabolic procedures such as methylation and one carbon cycle and its deficiency can cause serious health problems, such as hyperhomocysteinemia, defective synthesis of neurotransmitters and fatty acids and more. However, it is not known if there is a link between vitamin B12 deficiency and the risk of GDM. The purpose of this study is to systematically investigate and meta-analyze the evidence that exists up to date for this association.

Methods: A comprehensive research was conducted in PubMed, Scopus and Cochrane Central Register of Controlled Trials up to November 30^th, 2018. Data are expressed as odds ratio (OR) with 95% confidence intervals (CI). The I² index was employed for heterogeneity.

Results: Six studies (n=1,810 pregnant women, 309 GDM cases) fulfilled eligibility criteria for qualitative and two studies for quantitative analysis. Women with vitamin B12 deficiency were at higher risk for developing GDM when compared with those who were vitamin B12 sufficient: OR 1.81 (95% CI, 1.25–2.63, I²: 0%). Due to the small number of studies, the role of potential confounders could not be clearly estimated.

Conclusions: Vitamin B12 deficiency seems to be associated with increased risk of GDM. The pathogenetic mechanisms for this association need to be clarified in future studies.