Prevention of folic acid-preventable spina bifida and anencephaly.

The results of the British Medical Research Council's randomized controlled trial proved that folic acid can prevent spina bifida and anencephaly. The trial provided critical scientific data upon which to base public health policy for preventing folic acid-preventable spina bifida and anencephaly. Within weeks of publication of the results, the Centers for Disease Control and Prevention in the US developed and issued guidelines for women who had had a pregnancy affected by spina bifida or anencephaly. A year later, the US Public Health Service issued the recommendation that all women of child-bearing age who are capable of becoming pregnant should consume 0.4 mg of folic acid per day. The Public Health Service needed a year to make inferential judgements about dose, target groups, safety, timing of ingestion, and existing and proposed vitamin and drug policies and regulations. Current policy discussions concern whether to permit manufacturers of vitamins or food products to claim that folic acid will prevent folic acid-preventable spina bifida and anencephaly and whether to allow a food staple to be fortified with folic acid.