Vitamin C And E Supplements Do Not Lower The Risk Of Pre-Eclampsia
In the latest trial, Lucilla Poston, Andrew Shennan and colleagues from King's College London, England, 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 seizures).
However, there was no evidence that women taking normal pregnancy multivitamin preparations increased the risk of low birthweight babies or caused any harm.
"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 women," states Professor Poston. "Our 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 and vitamin E in pregnancy. There was, however, no evidence that taking the small doses of vitamins in pregnancy-specific multivitamin preparations gave any cause for concern.''
The vitamins used in this trial are not the same as folic acid supplementation, which is recommended prior to conception and in early pregnancy to reduce the risk of neural tube defects.