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2007-9-3 17:32:17 |
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Women can substantially reduce their baby's odds of being born with a facial cleft if they take folic acid supplements early in their pregnancy, a U.S. study suggests. Researchers at the National Institute of Environmental Health Sciences (NIEHS) found that 400 micrograms a day of folic acid reduced by one third the baby's risk of isolated cleft lip (with or without cleft palate). "These findings provide further evidence of the benefits of folic acid for women," said Allen J. Wilcox, M.D. Ph.D., lead NIEHS author on the new study published online in the British Medical Journal. "We already know that folic acid reduces the risk of neural tube defects, including spina bifida. Our research suggests that folic acid also helps prevent facial clefts, another common birth defect." Many countries including the U.S. have already fortified flour or wheat products with folic acid or folate to reduce the risk of neural tube defects. Folic acid is a B vitamin found in dark green, leafy vegetables such as spinach, whole wheat bread, lightly cooked beans and peas including lentils, Garbanzo beans and Lima beans, and also in fortified cereals and enriched grain products. The recommended daily dietary allowance for folic acid or folate is 400 mcg per day for adults, 600 mcg per day for pregnant women and 500 mcg per day for breastfeeding mothers. Previous studies have indicated that supplementation of folic acid may reduce the risk of orofacial clefts, but results were not consistent due to the design and size of the studies. "Folic acid deficiency causes facial clefts in laboratory animals, so we had a good reason to focus on folic acid in our clefts study," said Wilcox. The researchers meant to establish an association between facial clefts and mothers' intake of folic acid supplements, multivitamins, and folates in diet during pregnancy. They found folic acid supplementation of 400 mcg or more per day decreased the risk of isolated cleft lip with or without cleft palate by one-third, but apparently had no effect on the risk of cleft palate alone. The study was population-based and conducted in Norway where processed food is not allowed to be fortified with folic acid and the rate of facial clefts is highest among European countries. In the study, the researchers followed 377 babies with cleft with or without cleft palate (CLP) and 196 with cleft palate only; as well as 763 babies with the conditions randomly selected from all live births in Norway as controls. For the study, two questionnaires were sent to each of the mothers participating in the study to collect information on their general health and diet or nutrition during their pregnancy. Based on the information collected, the researchers estimated that 22 percent of isolated CLP cases in Norway could be avoided if all pregnant women took 400 mcg of folic acid per day. In the United States, about one in every 750 babies is born with cleft lip and/or palate, according to NIEHS. This is to say that 6,600 babies are born with cleft in the U.S. each year. "A mother's nutrition during pregnancy is clearly an environmental factor that can affect the health of her fetus," said NIEHS Director David A. Schwartz, M.D. Other factors may also contribute to the risk of cleft. The NIEHS researchers are continuing to investigate other environmental exposures that increase the risk of facial clefts. Acknowledgement: The article contains content from a new release of NIEHS ### |
