Dr. Mills:
-- the incidence rate, to start, is about one per 2,000. Now, it used to be one per thousand, and folic acid fortification of food has lowered the rate dramatically. And when the embryo is forming the central nervous system, it happens by folding a portion of the embryo into a tube, and that forms the brain and the spinal cord. And when that folding fails to be completed, and doesn’t close, then you can get a major defect in either the brain or the spinal cord. And these are both very devastating defects.

Well, as a little prelude, I should say that a major discovery a few years ago was that you could prevent a lot of neural tube defects by taking folic acid, and B12 is very closely related to folic acid biochemically, and they are involved in one key reaction. And it’s been shown several times previously that people who have children with neural tube defects have lower vitamin B12 levels during pregnancy. So we wanted to pursue that, and find out just how high a level of B12 you needed to be protected from that risk.

Yes, and in fact, I think the most interesting thing about our findings it that women who have a deficiency level of B12 have about five times, a five hundred percent increase in the risk for having a baby with a neural tube defect. And women who have a level that’s sort of in the below normal, but not totally deficient, range have about a three times increased rate. So that’s very important information for women who are trying to become pregnant.

Well, Ireland has traditionally had a very high level of neural tube defect problems in pregnancy. In fact, they call it “The Curse of the Celts,” there, and it’s probably partially genetic, and partially because of diet. So we have been doing research there, because it’s an area where they have a lot of people with the problems, and it enabled us to find women who were not exposed to a lot of supplements that contained either folic acid or B12.

Well, it’s very important that women get folic acid, because that is the major protective item, and although foods in the U.S. contain folic acid now, women should still take a supplement that has 400 micrograms of folic acid. The point that we’re making in our study, that’s new, is that women also should be aware of the fact that they need adequate B12. And two groups of women are at risk: those who are vegans, who may not be getting B12 in their diets; and women who have an absorption problem, any gastrointestinal problem that can interfere with vitamin absorption. And their physician should be able to tell them if they are at risk.

[end of transcript]

Video: Low Levels of Vitamin B12 May Increase Risk for Neural Tube Defects.