Gestational Diabetes 1.9 X more likely if low vitamin D – review

Vitamin D and Gestational Diabetes Mellitus: A Systematic Review Based on Data Free of Hawthorne Effect

Yanbo Zhang, Yunhui Gong, Hongmei Xue, Jingyuan Xiong, Guo Cheng

BJOG online: 15 December 2017, DOI: 10.1111/1471-0528.15060 V

Background: Gestational diabetes mellitus (GDM) is an increasingly prevalent disorder, associated with low blood vitamin D (VD) level.

Objectives: To evaluate the relationship between VD and GDM.

Search Strategy

EMBASE, MEDLINE, Cochrane library and China Biology Medicine disc were searched till May 2017. The references of previous studies were screened.

Selection Criteria

Observational studies on the relationship between VD and GDM free from Hawthorne effect and randomized controlled trials of VD supplementation during pregnancy for preventing or treating GDM were included.

Data Collection and Analysis

Data and information of included articles were extracted by duplicate using piloted tables. Newcastle-Ottawa Scale and Cochrane Handbook were used for quality assessment. Random-effects models were used for meta-analyses. Heterogeneity tests, sensitive analysis, and analysis of publication bias were conducted.

Main Results

Eighty-seven observational studies and 25 randomized controlled trials involving 55859 and 2445 subjects respectively were included. Low blood VD level during pregnancy was associated with a higher risk of GDM (OR = 1.850, 95% CI: 1.471, 2.328). Blood VD level for subjects with GDM were lower than the controls. Blood VD level was associated with fasting plasma glucose (FPG) and HOMA-IR (r = -0.100 and -0.351), whereas the correlation between blood VD level and fasting insulin (FINS) might be concealed by publication bias. VD intervention during pregnancy could change blood level of VD, FINS, FPG, HOMA-IR, glutathione, C-reactive protein, and lipid.

Conclusions

Low blood VD level could increase the risk of GDM, and VD supplementation during pregnancy could ameliorate the condition of GDM.