Oct. 26, 2000 -- Federal health officials say that by fortifying foods with folic acid, the U.S. is making good progress in trying to reduce the number of spinal birth defects that occur each year in this country.
In a report released Thursday, the CDC announced that over the past seven years, American women have significantly increased the levels of folic acid in their blood. Some measures show the amounts have more than doubled during that time among women involved in ongoing federal studies.
"That's great news," David Fleming, MD, tells WebMD.
The CDC's deputy director for science and public health says there's no question folic acid helps pregnant women avoid spinal tube birth defects like spinal bifida. About 20 years of scientific data support the concept. The challenge has been to try to find ways to get women to increase their levels of vitamin B, he says.
In 1996, the government ordered foods like flour and grain products to include folic acid. Women also can get folic acid with vitamin supplements.
The recent CDC study was based on comparisons of women's folic acid levels in 1999 and in 1992, which was long before folic acid fortification happened.
"This is absolutely the first time seeing that fortifying food is succeeding," Fleming says. "We're doing good work."
Researchers found blood levels of folic acid more than doubled during the seven-year period. Measuring folic acid levels in red blood cells is even more accurate, and Fleming says what is so encouraging is that the average folic acid level in red blood cells already exceeded the CDC's year 2010 goal.
The CDC noted that women of childbearing age are recommended to get 0.4 mg of folic acid each day, and if every woman does so, the number of spinal tube birth defects -- about 4,000 annually -- could be cut in half.
Fleming says that it is a good idea for all women who could become pregnant to get enough folic acid. Damage can occur to the developing baby long before a woman knows she is pregnant, so having a good baseline level of the vitamin can help avoid problems.
The next step for the CDC is to demonstrate that the rise in folic acid levels caused a reduction in the number of spinal tube birth defects. Fleming says those studies are coming, possibly "within a year or two."
He notes the CDC also is continuing to collect and test blood samples to determine if female minority populations also show a rise in blood folic acid levels. The data released Thursday show the overall average is on the rise, but there just have not been enough minority members in the study to be able to make conclusions about them specifically, he says.
Donald Mattoon, MD, medical director for the March of Dimes, told The Associated Press that the CDC study is an important step that "does suggest that food fortification may have had an impact." But he also cautioned that variations among minorities and socioeconomic groups were not considered.