Vitamin D deficiency raises preeclampsia risk in pregnant women

12 September, 2007

Pregnant women who have low levels of vitamin D face a five-fold risk of preeclampsia, a serious complication during pregnancy which can lead to death of the fetus.

Researchers from the University of Pittsburgh Schools of the Health Sciences, the United States, say there is a risk of preeclampsia even with supplementation of up to 400 international units (IU) of vitamin D.

The study, published in the Journal of Clinical Endocrinology and Metabolism, found that Vitamin D supplementation in early pregnancy should be explored for preventing preeclampsia and promoting neonatal well-being.

Preeclampsia is marked by soaring blood pressure and swelling of the hands and feet, and is the leading cause of premature delivery and maternal and fetal illness and death worldwide, believed to contribute to 76,000 deaths each year.

Preeclampsia is a dangerous condition for pregnant women, often forcing women to deliver prematurely to protect her health and the baby’s.

Preeclampsia, also known as toxemia, affects up to 7% of first pregnancies. Health care costs associated with preeclampsia are estimated at $7 billion a year in the United States alone, according to the Preeclampsia Foundation.

The new study adds to an ever-growing weight of the importance of vitamin D, which has been linked to a host of health benefits, including improving diabetes, heart health, breast cancer, and colon cancer.

According to Lisa Bodnar, lead author of the study, the results showed that maternal vitamin D deficiency early in pregnancy is a strong, independent risk factor for preeclampsia. Women who developed preeclampsia had vitamin D concentrations that were significantly lower early in pregnancy compared to women whose pregnancies were normal.

Even though vitamin D deficiency was common in both groups, the deficiency was more prevalent among those who went on to develop preeclampsia.

The researchers compared blood samples taken throughout the pregnancies of 55 women with preeclampsia and 220 women without the condition. Investigators tested these blood samples, as well as umbilical blood from the newborns, for vitamin D levels.

Even a small decline in vitamin D concentration more than doubled the risk of preeclampsia, says James M. Roberts, MD, senior author of the study. He explains: “Since newborn’s vitamin D stores are completely reliant on vitamin D from the mother, low vitamin levels also were observed in the umbilical cord blood of newborns from mothers with preeclampsia.”

Being a vitamin closely associated with bone health, vitamin D deficiency early in life is associated with rickets, a disorder thought to have been eradicated in the United States over 50 years ago, as well as increased risk for Type 1 diabetes, asthma, and schizophrenia. In the developing world, preeclampsia accounts for up to 80% of maternal deaths.

Even in the developed countries, preeclampsia remains the leading cause of maternal death. Infants born to mothers with preeclampsia have a risk of mortality five times greater than those born to women with normal pregnancies.

In the United States alone, nearly 15% of pre-term deliveries are a result of preeclampsia.