Falling Folic Acid Levels Portend Problems

A few weeks ago, I attended the Medicaid Commissioner’s Perinatal Task Force meeting in my home state of South Carolina. A featured presenter at that meeting was Dr. Roger E. Stevenson from the Greenwood Genetic Center who reminded us of the need to increase our vigilance regarding dietary intake of folic acid in women of childbearing age. Our part of the country has the dubious distinction of being one of the hotbeds for neural tube defects (spina bifida; anencephaly; encephalocele) in the U.S. But medical leaders from our state, at the forefront, Dr. Stevenson and colleagues, also played a key role in convincing the FDA in the late 1990’s to mandate folic acid supplementation in foods, partly, as the result of the successes experienced with such programs in our own state earlier in the 1990’s.

In 1992, 1 out of every 500 babies conceived in the State of South Carolina had a neural tube defect (NTD). By 2004, that number had been reduced to only 1 in 1300. It is estimated that with adequate folic acid supplementation, and programs designed to identify women at increased risk based on family or previous obstetrical histories, at least 50% of those NTDs could have been prevented as well. The value of supplementation was most clearly demonstrated here in the follow-up of women who had previously had a baby with a neural tube defect. Among the 362 who were placed on folic acid above that obtained by diet alone, none had a subsequent baby with an NTD. Of the 62 who did not take a supplement, 3 (5%) had another child with an NTD. This is consistent with the worldwide baseline recurrence risks of 3-5% (the risk is 7-10% if there have been two affected babies).

Dr. Stevenson estimated that with adequate folic acid prior to conception and during the first trimester (remember, the neural tube is completely closed by 28 days after conception, only two weeks past the first missed menstrual period), 60 NTD babies could be prevented each year in our state. Twenty-five of those babies would have such severe defects that they would succumb early, however, of the 35 who survived, the average cost for care of these children is $425,000, or $15,000,000 added to health care costs each year! If one considers that certain classes of congenital heart defects (the most common abnormalities found after delivery), and perhaps other abnormalities such as cleft lip and palate, might also be prevented in part by folic acid supplementation, the overall savings to health care costs could easily be 2-3 times that.

Despite the success of dietary education and folic acid supplementation programs, a recent concern raised in the CDC’s Morbidity and Mortality Report of January 5, 2007, is that surveys indicate blood folate levels have actually been decreasing in recent years. It was pointed out that with folic acid supplementation of cereals, grains, and flours, median folic acid levels in women aged 15-44 years increased from 4.8 ng/nL during 1988-1994 (presupplementation) to 13.0 ng/mL in 1999-2000. Between then and 2004, there has been a decline each year and in every ethnic group. The largest percentage decrease was noted in non-Hispanic whites (from 13.4 down to 11.3 ng/mL), but of greater concern is the decrease in ethnic groups that entered the 21st century with suboptimal levels to start with (non-Hispanic blacks going from 10.0 to 8.5 ng/mL and Hispanics from 11.1 to 10.0 ng/mL).

Reasons for this are not entirely clear. It has been hypothesized that the obesity epidemic may require that we reevaluate the adequacy of current recommendations for supplementation. Others have suggested that the “low carb craze” has reduced the intake of grains, flour, and cereals that are the foods primarily ‘supplemented’ by FDA mandate. Regardless, the overriding concern is that if the current trend continues, we run the risk of losing all the ground we have gained in reducing the serious and debilitating birth defects that are preventable by adequate nutritional intake of folic acid.

The bottom-line is that all women of childbearing age (whether or not you are anticipating a pregnancy) eat a healthy diet that includes foods such as fortified breakfast cereals, green leafy vegetables, broccoli, orange juice, black beans, peanuts, enriched breads and pasta. In addition, it is strongly recommended that women take a daily multivitamin supplement that contains at least 400 micrograms of folic acid, especially, if they are considering or trying to get pregnant. If a woman has previously had a baby with a neural tube defect (or any other abnormality that might be preventable by folic acid), she should take 4000 micrograms (4 mg) of folic acid daily prior to conception and during the first trimester of pregnancy.

Labels: congenital heart defects, folic acid, neural tube defects, NTD

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