Vitamin D, known mostly for its effect on bone health, is also an important factor in maintaining a healthy pregnancy.
Preeclampsia leads to about 18 percent of all maternal deaths in the United States. However, in a recent study, mothers with a vitamin D sufficiency were 40 percent less likely to develop the severe form of the condition.
The two main sources of vitamin D are; naturally, absorbed through the skin from sunlight, or through oral ingestion of foods. Pregnancy is also a known risk factor for vitamin D deficiency.
The researchers suggested that further exploration into the role of vitamin D in reducing the risk of preeclampsia is warranted. They cautioned that women should not automatically take vitamin D supplements during pregnancy as a result of these findings.
"Talk to your doctor about which supplements contain sufficient amounts of vitamin D."
The study was led by Lisa Bodnar, PhD, MPH, RD, of the University of Pittsburgh Graduate School of Public Health. The research team examined the blood samples from 2,986 mothers who had not developed preeclampsia during pregnancy and from 717 mothers who did develop the condition.
The samples were collected from 1959 and 1965 at 12 US sites enrolled in the Collaborative Perinatal Project. The blood was well-preserved and researchers were able to successfully test for vitamin D levels.
The study used the current definition of preeclampsia and applied it to measurements of blood pressure and urinary protein taken at the time of the study. Blood samples were taken every eight weeks as well as the day of labor and throughout post-pregnancy.
The researchers controlled for race, pre-pregnancy body mass index, previous pregnancies, smoking, diet, physical activity and sunlight exposure, all factors that could have affected vitamin D status.
The research determined that vitamin D levels were associated with a 40 percent reduction in the risk of developing severe preeclampsia but there was no relationship between vitamin D levels and mild preeclampsia. The study found that the overall risk, regardless of vitamin D levels, of developing preeclampsia was less than 1 percent.
"Scientists believe that severe preeclampsia and mild preeclampsia have different root causes," said senior author Mark A. Klebanoff, M.D., M.P.H., Center for Perinatal Research at The Research Institute at Nationwide Children's Hospital and the Department of Pediatrics at The Ohio State University College of Medicine. "Severe preeclampsia poses much higher health risks to the mother and child, so linking it with a factor that we can easily treat, like vitamin D deficiency, holds great potential."
This research was published in the March edition of the Journal of Epidemiology and was funded by the National Institute of Health. No conflicts of interest were reported.