Timing is everything: folate supplements seem to prevent premature births.

RODALE NEWS, EMMAUS, PA—According to surveys conducted by the March of Dimes, just 40 percent of American women of childbearing age take a daily folic acid supplement—despite being strongly encouraged to do so by the U.S. Public Health Service to prevent neural tube defects (such as spina bifida) in their unborn babies. Now, a new study by Texas researchers provides a second, equally compelling reason to get ample folic acid, or folate: The vitamin also seems to prevent preterm births and the health complications that accompany them. Folate is a B vitamin found naturally in some foods; the version used in supplements and fortified foods is called folic acid.

THE DETAILS: Lead study author Radoslaw Bukowski, MD, associate professor of obstetrics and gynecology at the University of Texas Medical Branch in Galveston, and his team asked nearly 35,000 pregnant women whether they took folic acid, and if yes, for how long they’d been doing so. About 20 percent said they had been taking folic acid supplements for a year or more; 36 percent said they had been taking them for less than a year, and 44 percent said they didn’t supplement at all.

Data collected by the researchers showed that taking folic acid supplements for a year or more reduced the participants’ risk of delivering a baby at 20 to 28 weeks by 70 percent, and of delivering a baby at 28 to 32 weeks by 50 percent. Taking folic acid supplements for less than a year reduced the risks by 50 percent and 30 percent, respectively.

WHAT IT MEANS: Dr. Bukowski and his colleagues aren’t sure why folic acid had this effect. What doctors do know is that folate helps to produce and maintain new cells, so it’s especially important during periods of rapid cell division and growth, such as pregnancy and infancy . “In our study, the beneficial effect of folic acid was very strong,” says Dr. Bukowski. “Plus, it was dose-dependent, meaning that the longer the women were taking it, the stronger the effect was.”

Here’s how to prevent preterm birth, one day at a time:

• Take a daily multivitamin. Since 1998, all U.S. grains have been fortified with folic acid to help prevent neural tube defects in unborn babies. Yet it’s still tough to get the 400 micrograms of folate a day that the U.S. public health service recommends from food alone. So pop a multi. It’s easy and it works. Also, include folate-rich foods—leafy green vegetables like spinach and turnip greens, citrus fruits and juices, and dried beans and peas—in your diet for extra coverage.

• Don’t wait. As this study shows, the longer you’ve been taking folate, the more benefit you get. And about 50 percent of pregnancies are unplanned, warns Dr. Bukowski. “So it’s better to take folic acid if it’s even possible you can get pregnant, instead of waiting until you’re actually planning a pregnancy,” he says.