Neural tube defects are congenital deformities that arise in the closure of the nervous system. Spina bifida and anencephaly are the two most common forms of neural tube defects seen. The defect causes paralysis in spina bifida and fatal brain deformation in anencephaly.
Although the defect can be diagnosed by antenatal ultrasound, nothing much can be done to correct the defect. The condition usually results in fetal loss or a severe structural abnormality which is difficult to be handled. However, the incidence of this anomaly can be significantly reduced by dietary supplementation with folic acid.
In 1991, scientists demonstrated that giving expectant mothers a synthetic version of folic acid could significantly reduce the risk of the birth defects. The natural form of the vitamin is found in green leafy vegetables, whole grains and citrus fruits, although it is less easily absorbed. In addition, folic acid has been shown to reduce blood levels of homocysteine, an amino acid that appears to be a risk factor for heart attacks and strokes.
The FDA made it mandatory in 1998 to add 140 micrograms of the vitamin to each 100 grams of grains that are labeled as