Maternal Use of Vitamins and Infant Congenital Malformation

Abstract

It is a generally held belief that maternal use of folic acid can drastically reduce the risk of a neural tube defect in the offspring. The data presented here do not support this idea: women who reported the use of folic acid in early pregnancy (most of them starting before the last menstrual period) did not have a lower rate of neural tube defect infants than expected. In contrast to this, there was a nearly significantly low rate of such defects after maternal use of multivitamins. The explanation to this is unclear. No beneficial effect on malformation rate was seen from use of vitamin B₁₂ and other B, C, or D vitamins. Two specific vitamins have been associated with a teratogenic effect: high doses of vitamin A and use of vitamin E. Only few women had used high doses of vitamin A and the literature on the subject reports different results. Such treatment during pregnancy should be avoided. An association between use of vitamin E and congenital malformations in the offspring is probably due to confounding by indication: subfertility and repeated previous miscarriages.