Early pregnancy vitamin D deficiency and gestational diabetes: Exploring the link

Diabetes, including gestational diabetes mellitus (GDM), and vitamin D deficiency or insufficiency (VDDI) are recognised public health problems. There is conflicting evidence regarding the relationship between vitamin D deficiency and GDM. The aim of this study was to explore the incidence of VDDI among pregnant women attending a maternity unit in Sydney, Australia, and the relationship between VDDI in early pregnancy and later development of GDM.

This was a prospective cohort study in which 25-hydroxyvitamin D was measured in pregnant women during 2011-13. Exclusion criteria included pre existing diabetes, bowel disease and reduced cognitive ability.

There were 785 women enrolled in the study and 42 excluded. Findings from this study did not show an association between VDDI in early pregnancy and development of GDM. Important predictors of GDM remained the well known risk factors: family history, ethnicity, body mass index and age.

Clinical conversations should continue to focus on proven modifiable factors such as weight management and the provision of timely testing appropriate to the risk identified through history-taking.