Women's Folic Acid Levels Improving

That should mean fewer serious birth defects, U.S. experts say.

By Carolyn Colwell
HealthDay Reporter
Friday, September 14, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

FRIDAY, Sept. 14 (HealthDay News) -- Blood levels of folic acid have increased among American women since the federal government mandated folate fortification to prevent birth defects, but questions remain as to how much folate is enough -- or too much.

A new study by the U.S. Centers for Disease Control and Prevention (CDC) finds that the number of women of childbearing age who have low blood folate levels has plunged following a 1998 federal mandate to enrich bread and grains with added folate.

The rate of low blood folate among women has fallen from 21 percent in 1988-1994 (before the fortification program) to less than 1 percent in 2003-2004, six years after fortification began.

That should mean fewer birth defects tied to low maternal folic acid levels in pregnancy. These anomalies include serious neural tube defects such as spina bifida. According to the March of Dimes, about 3,000 pregnancies are afflicted with these defects each year.

"Clinical trials have shown that folic acid supplementation effectively reduces the number of neural tube defects," said the study's lead author Christine M. Pfeiffer, acting chief of the Nutritional Biomarkers Branch at the CDC.

Her team published its study in the September issue of the American Journal of Clinical Nutrition.

Data used in the study was taken from the National Health and Nutrition Examination Surveys for the years 1988 through to 2004.

According to the CDC analysis, folate levels have continued to rise since 1998, although there was a slight dip in women's folate concentrations between the 2001-2002 and 2003-2004 surveys. However, average blood levels were still well above federal goals for red blood cell folate for women aged 15-44, Pfeiffer said.

The recent small dip in women's folate levels may have stemmed from the surge in popularity for low-carbohydrate diets, which may have prompted many women to move away from (fortified) bread and baked goods, the researchers said. However, "the slight downward trend after fortification seems unlikely to be functionally important" in terms of mom and baby's health, the study authors added.