Vitamin D is necessary for the intestines to absorb dietary calcium. Vitamin D comes from food and is also produced by the skin upon exposure to sunlight. Active children and young adults living in sunny regions can produce most of the vitamin D they need from their skin. In areas with insufficient sunlight, or in colder areas in winter, adequate vitamin D cannot be produced by the skin. Vitamin D deficiency is common among the elderly.
Pre-eclampsia is a condition of pregnancy that usually begins with high blood pressure. The disorder may also lead to seizures, kidney failure or stroke. It slows the growth of the fetus, can cause early delivery, and can be fatal for the mother and the infant. The cause is unknown and there is no treatment, except to manage the symptoms.
In the new study, "women who developed pre-eclampsia had vitamin D concentrations that were significantly lower early in pregnancy compared to women whose pregnancies were normal," lead author Dr. Lisa M. Bodnar, from the University of Pittsburgh, said in a statement. "And even though vitamin D deficiency was common in both groups, the deficiency was more prevalent among those who went on to develop pre-eclampsia."
Vitamin D has been shown to influence pathways involved in the development of pre-eclampsia, "yet the vitamin D/pre-eclampsia relation has not been studied," Bodnar's team notes in their report.
To investigate, they measured vitamin D levels in banked sera from 55 pregnant women who developed pre-eclampsia and from 219 who did not.
The average 25-hydroxyvitamin D level for women who developed pre-eclampsia was 45.4 nmol/L compared with 53.1 nmol/L in the control group -- a significant difference.
Moreover, the risk of pre-eclampsia rose with decreasing levels of vitamin D in early pregnancy, the authors found.
If the current findings are verified in other studies, the investigators suggest, "Vitamin D supplementation in early pregnancy should be explored as a safe and effective means of preventing pre-eclampsia and promoting neonatal well-being."