High doses of vitamins not good for pregnant women

There had been hope that if women took high doses of vitamins C and E during pregnancy their risk for pregnancy complication, particularly high blood pressure or preeclampsia, would be reduced. That doesn’t seem to be supported by the evidence collected so far.

After reviewing existing data culled from over 20,000, researchers have found no benefit to taking high doses of vitamin C, as much as 1,000 milligrams, and vitamin E, up to 400 IUs, instead of the regular amounts in prenatal vitamins. Instead, other risks were identified from taking high doses of the supplements.

Preeclampsia is characterized by high blood pressure, protein in the urine and swelling, notably of the face and extremities. It occurs in about five percent of American pregnancies on average each year. Without treatment, it can be fatal to both mother and baby.

Vitamin C has been thought to play a role in placenta health. Low amounts are associated with the early “breaking of water”, rupture of uterine membrane. In preeclampsia sometimes there is an early separation of placenta from the uterus. But taking vitamin C does not alleviate the risk.

In fact it can make it worse. In some women they were more likely to develop high blood pressure with the protein in the urine and still experience early rupture of membranes. On the flip side, they did find that there were fewer instances of the placenta pulling away from the uterine wall.

“The finding of the decreased risk of abruption placentae in women receiving vitamins C and E certainly may provide some insight into potential causes of abruption placentae and can guide areas of future research,” said Dr. Sonia Hassan of Wayne State University.

Source: American Journal of Obstetrics & Gynecology, Reuters