The Effects of Serum Folic Acid and Vitamin B12 on the Risk of Gestational Diabetes Mellitus

Abstract

Purpose

In order to gain more knowledge on the risk of gestational diabetes mellitus (GDM), and to provide evidence for clinical guidance on the optimum level of serum folic acid and vitamin B12, this study aimed to clarify the relationship between serum folic acid and vitamin B12 and the risk of GDM.

Patients and Methods

This retrospective case−control study was conducted based on the clinical information system of the Maternal and Child Health Hospital of Hubei Province. Clinical data including maternal socio-demographical characteristics, serum folic acid, and vitamin B12 were collected. Logistic regression analyses and restricted cubic splines were performed to examine the impact of serum folic acid and vitamin B12 on the risk of GDM.

Results

Significantly elevated risks of GDM were observed in groups with high serum folic acid concentration (OR = 1.84, 95% CI: 1.07−3.16), and in low vitamin B12 concentration (OR = 2.14, 95% CI: 1.26−3.65). After stratified by age, the increased risk of GDM was still noticed in a low level of vitamin B12 among mothers aged <30 years (OR = 4.76, 95% CI: 1.45−15.61). In mothers with pre−pregnancy BMI <24, elevated risk of GDM was significantly associated with a high folic acid (OR = 2.09, 95% CI: 1.11−3.93) or a low vitamin B12 concentration (OR = 2.24, 95% CI: 1.22−4.14). Moreover, the risk of GDM was on the decline with the increased level of folic acid in the beginning, and it started to manifest an upward trend when the serum folic acid reached 19.02 ng/mL.

Conclusion

This study demonstrated that serum folic acid excess or vitamin B12 deficiency could contribute to the increased risk of GDM, and revealed the potential side effect of serum folic acid overdose. As serum folic acid and vitamin B12 tests are widely applied in clinical practice, this finding could help clinicians to evaluate maternal risk from a new perspective.

Keywords:

• gestational diabetes mellitus
• folic acid
• vitamin B12
• age
• BMI

Abbreviations

CI, Confidence Interval; GDM, gestational diabetes mellitus; IQR, interquartile range; OR, Odds Ratios; RCS, restricted cubic spline.

Data Sharing Statement

The dataset used and/or analyzed during the current study is available from the corresponding author on reasonable request.

Ethics Approval and Consent to Participate

This study was conducted in accordance with the Declaration of Helsinki and approved by the Ethics Committee of Maternal and Child Health Hospital of Hubei Province (2021IECXM047).

Patient Informed Consent

Patient informed consents were not collected in this study because the data was obtained retrospectively from the clinical information system without any individual patient identifiers. The patient informed consent has been exempted by the Ethics Committee of Maternal and Child Health Hospital of Hubei Province.

Author Contributions

All authors have made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas, and they have drafted, or written, or substantially revised or critically reviewed the article. All authors agreed on the journal to which the article submitted, gave final approval of the version to be published, and agreed to be accountable for all aspects of the work.

Disclosure

The authors have no potential conflicts of interest and confirm that this study has not been previously been published elsewhere by any of the authors.

Additional information

Funding

This study was funded by the Maternal and Child Health Hospital of Hubei Province Research Project [grant No. 2021SFYM007].