High level of vitamin D not associated with lower risk of gestational hypertension

According to a new study in the Annals of Epidemiology, high levels of vitamin D do not prevent hypertension in pregnancy. The report adds to the literature on vitamin intake and preeclampsia while contradicting some previous reports that have suggested a link between low maternal levels of the vitamin and the disorder.

Researchers at Beth Israel Deaconess Medical Center and Boston Children's Hospital looked at women enrolled in the Project Viva prenatal cohort (n = 2100) in Massachusetts, examining the associations between 25(OH)D levels obtained at 16.4-36.9 weeks’ gestation with hypertensive disorders during pregnancy, including preeclampsia (56/1591, 3.5%) and gestational hypertension (109/1591, 6.9%).

The investigators did not find an association between 25(OH)D concentration (mean 58, standard deviation 22 nmol/L) and preeclampsia. With every 25 nmol/L increase in 25(OH)D, the adjusted odds ratio (aOR) for preeclampsia was 1.14 (95% confidence interval [CI], 0.77-1.67). On the other hand, higher 25(OH)D concentration was associated with higher odds of gestational hypertension; aOR for the condition 1.32 (95% CI, 1.01-1.72) for every 25 nmol/L increase in vitamin D.

Concluding that the study did not support the hypothesis that higher 25(OH)D levels were associated with lower overall risk of hypertension during pregnancy, the study authors indicated that future studies of vitamin D supplementation in pregnant women should monitor for patterns of gestational hypertension. 

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