In 1999, results of a small randomised trial suggested that vitamin C and E could reduce the incidence of pre-eclampsia in pregnant women (See Lancet 1999; 354: 810-816). In the latest trial, Lucilla Poston, Andrew Shennan and colleagues from King's College London, UK investigated the effect of the supplements in a much larger group of women who were at risk of pre-eclampsia from a wide range of different clinical conditions.
The investigators recruited over 2400 women at high risk of pre-eclampsia from 25 hospitals in the UK. Half were assigned 1000mg of vitamin C and 400 IU (International Units) of vitamin E and half placebo daily from the second trimester of pregnancy until delivery. They found that the incidence of pre-eclampsia was similar in both groups (15% vs 16%). The investigators also found that more low birthweight babies were born to women who took the supplements when compared with those on placebo (28% vs 24%). Women receiving the supplements also needed more treatment, including steroids, antihypertensive medication, and magnesium sulphate (to prevent fits). However, there was no evidence that women taking normal pregnancy multivitamin preparations increased the risk of low birthweight babies or caused any harm.
Professor Poston states: "Although we gave high doses of vitamin C and vitamin E to participants in this trial, they were below the maximum recommended intake in pregnant womenOur findings of an increase in low birthweight and an increased need for treatment, without any benefit in regard to pre-eclampsia suggest contraindication of these high doses of vitamin C
Contact: Joe Santangelo