Folic acid, already recommended as a nutritional supplement during pregnancy to prevent spina bifida, also reduces the risk of cleft lips and cleft palates by 25% to 50%, according to researchers at the California Birth Defects Monitoring Program.
Dr. Gary Shaw and his colleagues at the monitoring program report Saturday in the international medical journal the Lancet that they compared the diets of 731 women who delivered a baby with a cleft lip or palate to 734 who did not. They found that the women with healthy babies were much more likely to have taken folic acid supplements or multivitamins fortified with folic acid or to have consumed breakfast cereals fortified with folic acid during the month before conception and in the first two months of pregnancy.
The new research is likely to bring increased pressure on the Food and Drug Administration to permit fortification of flour and bread with folic acid. The FDA has had such a proposal under consideration for more than a year because of the evidence that the additive largely prevents spina bifida, but the agency has moved cautiously because overdoses of the supplement can cause problems.
Researchers have long known that folic acid deficiencies can interfere with the replication of DNA, which progresses at a rapid rate during the early stages of pregnancy. Mistakes in replication, which can produce birth defects, are much more likely to occur in the absence of sufficient quantities of folic acid.
Cleft lips and palates are about twice as common as spina bifida, affecting an estimated 1,200 children born in California each year and perhaps as many as 7,000 nationwide. Shaw pointed out that cleft lips and palates, while not as life-threatening as spina bifida, are nonetheless serious birth defects.
"A lot of people have the mistaken belief that cleft lips and palates, because they can be repaired, are not serious defects," he said. "That is not the case. The children undergo three to four surgeries in the first two years of life, and that is not an insignificant thing to the child or to the family. The anguish is not small."
The defects, which involve a split lip that can be split well into the nose, or a hole in the roof of the mouth, make it very difficult for newborns to feed because they cannot suck properly. Even after the problems are surgically repaired, children can have many difficulties with speech and also have an above-normal incidence of ear infections.
The estimated medical costs for children born in California with the condition in 1988--the most recent year for which figures are available--were about $90 million, Shaw said.
The U.S. Centers for Disease Control and Prevention recommends that women--particularly in the 15-45 age range--consume about 0.4 milligrams of folic acid daily. The amount consumed through a normal, healthy diet is about 0.2 to 0.3 milligrams, and most supplements contain about 0.4 milligrams. Shaw and his colleagues did not measure how much the women in their study consumed.
CDC also recommends that women consume no more than about 1 milligram of folic acid per day. The major worry is that large amounts can cloak the symptoms of pernicious anemia--which is caused by a Vitamin B12 deficiency--so that a woman does not receive treatment for the disorder, which can be fatal.
Shaw cautioned that the positive effects they observed could be due to other components of the fortified cereals and nutritional supplements. "We studied women who took vitamins, and those products contained a lot of constituents," he said. One of those other constituents could be the active protectant, he said.
Nonetheless, he said, taking folic acid before and after conception remains good advice.