Pregnant women with pre-eclampsia, also known as toxemia, suffer from elevated blood pressure as well as swelling of the hands and feet. Pre-eclampsia is the leading cause of premature delivery and maternal and fetal illness worldwide.

Lisa M. Bodnar of the University of Pittsburgh Graduate School of Public Health and colleagues evaluated data and banked blood samples taken from 1,198 women and newborns from 1997 and 2001 at Magee-Womens Hospital of the University of Pittsburgh Medical Center.

Low vitamin D early in pregnancy was associated with a five-fold increase in the odds of pre-eclampsia. However, researchers said they were troubled by the fact that many of the women reported taking prenatal vitamins, which typically contain 200 to 400 International Units of vitamin D, reported the study published in the Journal of Clinical Endocrinology and Metabolism.

Vitamin D deficiency early in life is associated with rickets as well as increased risk for type 1 diabetes, asthma and schizophrenia, added Bodnar.