There’s more evidence of the importance of vitamin D to health: Recent research shows that women who are deficient in the nutrient early in pregnancy are more likely to develop preeclampsia, a serious pregnancy complication involving high blood pressure and protein in the urine.
The researchers measured vitamin D levels in serum samples from 55 women who developed preeclampsia and 219 who did not. The samples had been taken before 22 weeks of pregnancy. (Preeclampsia usually occurs after 20 weeks, in middle to late pregnancy.) Cord serum samples from infants were used to measure vitamin D levels in the newborns.
“Mothers who were vitamin D deficient in early pregnancy were about five times as likely to develop preeclampsia as women who were not vitamin D deficient,” says Lisa Bodnar, a study author and assistant professor at the University of Pittsburgh. “As vitamin D status declined, the risk of preeclampsia increased. … So basically the better your vitamin D status got, the lower your risk of preeclampsia.”
In addition, the newborns of preeclamptic mothers were about twice as likely to be vitamin D deficient as those born to healthy mothers.
Bodnar says vitamin D may help reduce the risk of preeclampsia because it plays a role in the development of the placenta and the regulation of blood pressure.
She notes that many researchers believe the current recommended daily intake of vitamin D (200 international units) may not be adequate to prevent vitamin D deficiency. “We do know from a lot of research that vitamin D deficiency is much more common than we ever thought it was — particularly in northern climates.”