Vitamin E is an anti-oxidant found naturally in foods like nuts, vegetable oil and broccoli. Earlier research had suggested that vitamin E, particularly taken with vitamin C, could help protect against miscarriage and pre-eclampsia.
However, Andrew Shennan, who led a two-year study at St. Thomas' Hospital in London, warned that pregnant women could be putting their unborn babies at risk by 'self-medicating' with high doses of vitamin E, reported the online edition of the Daily Mail.
The researchers studied 2,400 pregnant women at risk of pre-eclampsia. Some of them took 250 mg of vitamin E and 1,000 mg of vitamin C each day from 14 weeks until they gave birth.
Those women who took high doses, which were typical to those found in supplements, developed pre-eclampsia sooner and had a more severe form of the illness, the study found.
Nineteen babies were stillborn to mothers taking vitamin E supplements, compared with just seven in the group, which did not take the pills.
In addition, the birth weight of the babies whose mothers had taken the vitamins was on average 60 grams less than the placebo group.
The study has been published in The Lancet and the New England Journal of Medicine.