Folic Acid Fortification Boosts B Vitamin in US

NEW YORK (Reuters Health) - Vitamin B levels have improved significantly in every segment of the US population since the Food and Drug Administration mandated folic acid fortification of enriched cereal-grain products in 1998.

"Folate fortification is an example of how easily the vitamin status of the entire population can be improved with a relatively simple and cost-effective measure," Dr. Christine M. Pfeiffer from the Centers for Disease Control and Prevention, Atlanta, told Reuters Health.

Folic acid is a synthetic version of folate, a member of the vitamin B complex. Food fortification was aimed largely at preventing birth defects that can occur when pregnant women are deficient in folate.

Pfeiffer and her colleagues used data from the National Health and Nutrition Examination Survey (NHANES) to examine blood levels of folate, vitamin B-12, homocysteine and methylmalonic acid in the US population before and after folic acid fortification of cereal-grain products began in 1998.

Homocysteine and methylmalonic acid, which are indicators of generalized inflammation and possible cardiovascular risk factors, usually decline when folate levels increase

Between NHANES III (1988-1994) and NHANES 1999-2000, average folate levels more than doubled, the investigators found. Vitamin B12 concentrations increased only slightly during the same interval.

These changes were evident in each sex and racial-ethnic subgroup, except for vitamin B12 in non-Hispanic blacks, the researchers report in the American Journal of Clinical Nutrition.

The prevalence of folate deficiency declined from 16 percent to 0.5 percent over the study period, the report indicates, and decreased even more significantly (from 20 percent to 0.8 percent) among women of childbearing age.

Children and the elderly also benefitted, the team reports

In the last survey, only 5 percent of the US population had high homocysteine levels and 2 percent had elevated methylmalonic acid levels.

"The US folic acid fortification program might have other benefits beyond the reduction of the incidence of (birth) defects," Pfeiffer said. "Due to the homocysteine-lowering effect of folate, reductions could be expected in the incidence of vascular diseases."

Mandatory folic acid fortification "may be the most important science-driven intervention in nutrition and public health in decades," writes Dr. Irwin H. Rosenberg from Tufts University, Boston, in a related editorial.

"However, this should not take away the focus from proper and balanced nutrition," Pfeiffer cautioned, "because there are many other compounds and factors contained in our daily food that can have a positive impact on health exceeding the benefit of a multivitamin or a vitamin added to food through fortification."

SOURCE: American Journal of Clinical Nutrition, August 2005.