A recent study examines the relationship between vitamin D levels in pregnant women and the risk for high blood pressure in pregnancy and pre-eclampsia.
Women often have low vitamin D levels during pregnancy. Some studies suggest that women with lower levels of vitamin D are at a higher risk for pre-eclampsia, a serious complication characterized by high blood pressure in pregnancy, among other symptoms.
A few recent studies indicated that vitamin D supplements may be beneficial during pregnancy, while others found no strong link between vitamin D supplementation and lower risk of high blood pressure or pre-eclampsia.
Research by a team of British, Dutch, Norwegian, and American scientists aimed to determine if certain genetic variations cause lower vitamin D levels and have an effect on high blood pressure or pre-eclampsia during pregnancy. Their work was recently published in The BMJ.
Using data collected from two previous European pregnancy studies, the current work analyzed data from a total of 7,389 women. Information about vitamin D levels, gestational high blood pressure, and pre-eclampsia were available for each participant. Additionally, data about genetic variants in four specific genes involved in vitamin D production were also collected.
After analyzing the data, the researchers found no strong evidence of vitamin D levels having an effect on high blood pressure or pre-eclampsia during pregnancy. Additional studies with a larger number of participants are needed.
Nonetheless, the U.S. Institute of Medicine recommends 600 IU of vitamin D daily for pregnant women. Health councils in the UK, the Netherlands, and Norway recommend 400 IU of vitamin D daily.
Written by Cindi A. Hoover, Ph.D.
Reference: Magnus et al. Vitamin D and risk of pregnancy related hypertensive disorders: mendelian randomisation study. BMJ 2018; 361:k2167. https://doi.org/10.1136/bmj.k2167
