BELFAST, England—Supplementation with vitamins C and E did not reduce risk of hypertension in pregnant women with type 1 diabetes in a study published in the June 26, 2010 early online addition of The Lancet (doi:10.1016/S0140-6736(10)60630-7). However, researchers noted the possibility that vitamin supplementation might be beneficial in women with a low antioxidant status.
Results of several trials of antioxidant use during pregnancy have not shown a reduction in pre-eclampsia, a medical condition in which hypertension arises in pregnancy, but the effect in women with diabetes was unknown.
Women from 25 U.K. clinics who had type 1 diabetes preceding pregnancy were enrolled in the multicenter randomized placebo-controlled trial. Between 8 weeks and 22 weeks of gestation, 762 women randomly received 1,000 mg vitamin C and 400 IU vitamin E (α-tocopherol), or a matched placebo daily until delivery. Between April 2003 and June 2008, women were randomly allocated to treatment groups (379 vitamin supplementation, 383 placebo).
Researchers found rates of pre-eclampsia did not differ between vitamin (15 percent, n=57) and placebo (19 percent, n=70) groups. However, researchers did find the supplements caused no adverse maternal or neonatal outcomes.