Prior to and early in pregnancy, less than one milligram of folic acid consumed each day could be all it takes to prevent neural tube defects (NTD), a congenital abnormality (see “What Are Neural Tube Defects?” page 80). Andrew Czeizel, M.D., director of the Department of Human Genetics and Teratology at the National Institute of Hygiene in Budapest, Hungary, reports that folic acid supplements taken at least one month before and for the first few months of pregnancy reduce the risk for NTDs.
Czeizel’s research and other studies on the importance of folic acid have prompted the U.S. Public Health Service to recommend that all women of child-bearing age capable of becoming pregnant consume 400 micrograms and pregnant women, 800 micrograms of folic acid a day to reduce the risk of having a baby with spina bifida or other NTDs.
In fact, the link between folic acid and birth defects is so strong that the Food and Drug Administration recently announced mandatory folic acid fortification of enriched breads and cereals by January 1998. Under the fortification program, the agency is requiring manufacturers to add from 430 micrograms to 1.4 milligrams of folic acid per pound of product to enriched flour, bread, rolls, buns, farina, corn grits, cornmeal, rice and noodle products. A serving of each of these products could provide about 10 percent of the daily value (formerly called recommended daily allowance, or RDA) of folic acid for pregnant women.
However, you can’t depend solely on fortification of processed foods to meet your folic acid needs. Stick with at least two to three daily servings of the ol’ standbys, dark-green leafy vegetables, or take a supplement.
Supplement Sensibly Most experts agree that food is your best source of nutrients. Problem is, many women don’t eat enough of the right foods during pregnancy to guarantee optimal intake, according to a 1993 study of pregnant and lactating women based on a U.S. Department of Agriculture (USDA) survey. “Three out of every four women in our study didn’t consume even one serving of dark-green leafy vegetables on a given day,” reports Lori Borrud, D.P.H., R.D., of the USDA.
When women aren’t getting what they need from their food, supplements become crucial. Besides the definite advantage of folic acid supplementation, many pregnant women may need iron supplements since they are at particular risk for deficiency. Up to 7.4 percent of women in their first trimester and up to 55 percent in their third trimester are iron-deficient, which places them at risk for preterm labor, low-birth-weight babies and stillbirths, say researchers at the University of Oklahoma. Up to 60 milligrams of iron can be taken during pregnancy, but always check with your doctor before taking any supplement.
Even with all the new research on the need for extra nutrients, supplementation can still be a mixed bag. “With all of the awareness among pregnant women about what vitamins and minerals they need before and during their pregnancies, we want to make sure they don’t consume too much,” says Nancy Butte, Ph.D., associate professor of pediatrics at Baylor College of Medicine, Houston and research scientist at the USDA Children’s Nutrition Research Center, Houston. “There are people who feel that if a little of something is good, more is better. That can be dangerous.”
Too much vitamin A poses the most danger to pregnant women. Researchers at the Boston University School of Medicine found that even moderate doses of this vitamin can cause birth defects. Women in this study who consumed 10,000 IU or more of vitamin A daily were at considerably higher risk of having babies with birth defects, including cleft palate and heart defects.