NEW YORK, Sep 14 (Reuters Health) -- Average US blood levels of folate -- a nutrient important in the prevention of birth defects -- have risen significantly after the federal government mandated that grain products be fortified with folic acid in 1996.
Starting in mid-1997, there has been "a steady increase" in average blood levels of folic acid in the US population, according to Dr. Jean Lawrence of Kaiser Permanente, Pasadena, California, and a team from the Centers for Disease Control and Prevention in Atlanta, Georgia. Their findings are published in the September 11th issue of The Lancet.
Low blood levels of folic acid during pregnancy have been associated with an increased risk for neural tube defects -- birth anomalies including serious conditions like spina bifida. To help reduce this risk, in 1996 the US Food and Drug Administration mandated folic acid fortification of grain-based products at a level of 140 micrograms per 100 g of cereal grain.
In their study, the researchers analyzed data on blood folate concentrations in nearly 100,000 samples submitted to Kaiser Permanente's Southern California endocrinology laboratory from 1994 to 1998.
The investigators report that the percentage of samples with low blood folate concentrations remained steady at about 1.3% for the first 3 years of the study, but by 1998, that figure was only 0.3%. Likewise, the number of samples with high serum folate concentrations increased during that same period of time, from around 25% to 45%.
"Our data suggest that serum folate values are rising. Folic acid fortification of food appears to be the most likely explanation," Lawrence and colleagues conclude.
