Research presented at the European Association for the Study of Diabetes Meeting reports that vitamin D deficiency during the first trimester of pregnancy is linked with a significantly increased risk for development of gestational diabetes.
This association has been seen before, but previous research results have been inconsistent due to confounding factors.
The study included 655 pregnant women aged 18 or older, 6-13 weeks into pregnancy. The researchers assessed vitamin D status at the start of the study (week 6-13 of gestation) and then assessed each participant for diabetes at week 24-28. Fifty-four of the women developed gestational diabetes (8%).
Twenty-six percent of the women were vitamin D deficient (<20 ng/mL) during their first trimester. Thirty-seven percent of women who developed gestational diabetes by the second trimester were vitamin D deficient.
These finding were statistically significant after controlling for age, season of sampling, vitamin D supplementation, and waist circumference. The risk for developing gestational diabetes increased by 40% for each standard deviation decrease in 25(OH)D levels (7.5 ng/mL).
Marilyn Lacroix, the researcher presenting the study, stated that they did not control for previous incidence of gestational diabetes, a factor which increases the risk of developing gestational diabetes a second time.
A European study is in progress to assess whether vitamin D supplementation will prevent gestational diabetes.