Until now, the thinking has been that folic acid is needed most during the first few weeks of pregnancy to prevent birth defects, but now, there is evidence that folic acid plays an important role for much longer than just the first trimester.
Later in the pregnancy, it is linked to brain development. Studies in mice at the Universtiy of North Carolina at Chapel Hill show cutting folic acid out of the diet during pregnancy drastically cuts the number of brain stem cells in babies.
"So, that is a very big effect, if you have half as many stem cells starting to form your brain, you are going to have less backup pathways, later in life you start losing nerve cells, and we all lose nerve cells by the age of 18. You will have less to lose before somebody notices that you are just not doing as well, so it could explain why what mother ate is important for what you are like later in life," says Dr. Steven Zeisel, UNCH School of Public Health.
Dr. Zeisel also says the findings are important for people because our brain development is similar to that in mice, and he says even though this is an early study, he thinks the findings are compelling enough to send a red flag to all women about the importance of pre-natal vitamins which include folic acid before and during pregnancy.
Researchers say they also have evidence that folic acid is important during the first months after pregnancy in breast milk, because a baby's brain is still developing and can benefit from the nutrient. Spina Bifida, the early birth defect in which the spinal cord doesn't close, and Anencephaly, a condition in which the brain doesn't form normally, can be eliminated between 50 and 85% of the time if women get sufficient folic acid before they become pregnant.
It's recommended women get 400 micrograms of folic acid, during pregnancy 800 micrograms. Besides supplements, the best sources of folic acid are green leafy vegetables such as spinach and greens, orange juice, and cereals fortified with the vitamin. A report on the findings appears in the January issue of the Journal of Nutrition. The National Institutes of Health and the Center for Environmental Health Susceptibility supported the new research.