A total of 680 healthy women age 22-35 were enrolled in the Diana Project to evaluate the effects of various vitamin and mineral supplementation on reproductive outcomes. At their 1st prenatal visit the women were asked whether they took prenatal vitamins, in particular, folate supplements, during their pregnancy. The women were followed to term and their children were assessed for neural tube defects (NTDs). 392 women took folate supplements and of these women, 164 gave birth to infants with NTDs. Of the women who did not take folate supplements, 166 had infants with NTDs.

A total of 680 healthy women age 22-35 were enrolled in the Diana Project to evaluate the effects of various vitamin and mineral supplementation on reproductive outcomes. At their 1st prenatal visit the women were asked whether they took prenatal vitamins, in particular, folate supplements, during their pregnancy. The women were followed to term and their children were assessed for neural tube defects (NTDs). 392 women took folate supplements and of these women, 164 gave birth to infants with NTDs. Of the women who did not take folate supplements, 166 had infants with NTDs.