Serum vitamin D insufficiency is related to blood pressure in diabetic pregnancy.

Background: Vitamin D deficiency in pregnancy has been associated with an increased risk of preeclampsia. However, the association between serum vitamin D and blood pressure in pregnant women has been scarcely evaluated, particularly in women with a high risk of developing hypertensive disorders of pregnancy. We sought to evaluate the association between serum 25-hydroxyvitamin D and blood pressure in pregnant women with gestational diabetes mellitus (GDM).

Methods: A cohort of 184 pregnant women with GDM was followed during the third trimester of pregnancy and early puerperium. Blood pressure was recorded in all prenatal visits, and serum vitamin D was measured by chemiluminescence immunoassay. Pearson's coefficients and multiple linear regressions were used to study predictors of blood pressure levels.

Results: Women with vitamin D insufficiency (<30ng/mL; n = 159) had higher systolic and diastolic blood pressure than the remaining participants. In white women (n = 136), serum vitamin D levels presented a significant negative correlation with systolic blood pressure at the beginning (r = -0.268; P = 0.002) and at the end of the third trimester (r = -0.203; P = 0.02), and vitamin D significantly affected systolic blood pressure after adjusting for confounders. This was not observed in women of other ethnicities.

Conclusions: In this cohort of pregnant women with GDM, vitamin D insufficiency was associated with higher blood pressure, and in white women, serum vitamin D was an independent predictor of systolic blood pressure during pregnancy.