Promoting folic acid

Prevention: The vitamin can reduce the risk of neural tube defects, but doctors and women haven't gotten the word

Health & Fitness

November 28, 1999|By Shari Roan | Shari Roan,Los Angeles Times

It's been seven years since federal health officials announced that folic acid was so effective at preventing a certain type of birth defect that all women of childbearing age should take it.

Last year, the government even mandated that cereal and grain products be fortified with folic acid -- a form of vitamin B -- to prevent neural tube defects, which involve the spinal cord. Now, however, public health leaders are facing the unsettling realization that none of their efforts have worked to prevent this serious type of birth defect.

The failure of women and their doctors to embrace the folic acid message has perplexed health officials, who say that as many as 2,000 to 2,800 cases of neural tube defects (out of the estimated 4,000 a year) could be avoided in the United States if all women of reproductive age consumed enough folic acid.

"Five years ago, we thought that if we just told people about it, they would naturally take it. We thought that would be enough," says Judith S. Gooding, director of the March of Dimes' folic acid campaign.

Women and their doctors may not realize that folic acid is only effective if taken in the first few weeks of pregnancy, before a woman even knows she's pregnant, Gooding says. For this reason, it's important for all women of reproductive age to consume 0.4 milligrams (or 400 micrograms) of the vitamin routinely in case they become pregnant. About half of all pregnancies are unplanned.

Getting enough folic acid through diet is extremely difficult, requiring women to eat several cups of foods high in folic acid each day. But getting women to take a vitamin every day -- often for years and even if pregnancy is not on a woman's radar screen -- has also proved to be an enormous challenge.

"The fact that we know how to prevent this defect hasn't had an effect," says Charlotte Dickinson, a researcher and expert on birth defects for the Centers for Disease Control and Prevention in Atlanta. "The real problem is getting people aware of what is going on."

Neural tube defects occur 18 to 28 days after conception. During this period, the small collection of fetal cells, which begins to grow as a flat patch, folds over and curves, with the edges forming what will be the spinal cord.

If the top of the spinal cord fails to close, a baby is born without a brain, a condition called anencephaly. This results in stillbirth or death within a day or so.

If the lower part of the neural tube doesn't close completely, the damage to the spinal cord causes spina bifida. Spina bifida can range from mild, such as difficulty walking, to severe, such as the inability to move limbs and mental retardation.

The actual cause of neural tube defects is not well understood. Since the defect occurs repeatedly in some families and is more prevalent among certain ethnic groups, such as Latinos, researchers believe genes may play a role.

"We don't know the causes of spina bifida or the mechanisms by which folic acid prevents spina bifida," says Dickinson. "We do know it works."

So, if the evidence is so strong and the defect is so horrendous, why aren't more women embracing the folic acid message?

Experts suggest the problem is a lack of awareness about taking the supplement for the entire course of a woman's reproductive years (roughly ages 13 through 45); physicians' unwillingness to take the time to counsel their patients; and the difficulty in getting enough folic acid from diet alone.

There are three ways to get folic acid: through one's regular diet, by eating fortified foods -- cereal, pasta and others -- or by taking folic acid supplements or a multivitamin containing folic acid. The vitamin is found naturally in leafy vegetables, fruit, legumes and liver. But most food products contain only small amounts of the vitamin.

"There are no randomized trials to show you can [get enough of the vitamin] by diet alone," Dickinson says.

There were high hopes that fortification of food would ensure that women could get enough of the vitamin through diet. But the government required such a low rate of fortification (each serving of an enriched grain must contain 10 percent of the recommended daily amount of folic acid) that it's still hard to consume enough, says Gooding.

The fortification rate was kept low, she says, because of a fear that too much folate -- about 1,000 micrograms per day -- can cause a condition called pernicious anemia, a dangerous blood disease, or can mask a vitamin B-12 deficiency.

Because only 3 percent of women will get enough folic acid by eating fortified foods alone, experts are continuing to push the FDA to allow food manufacturers to include higher levels of the vitamin in their products, says Gooding, who, with Dickinson, spoke to representatives of the dietary supplement industry at the annual meeting of the Council for Responsible Nutrition in Rancho Mirage, Calif.

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