One of the most exciting medical findings of the last part of the 20th century is that folic acid, a simple, widely available, water-soluble vitamin, can prevent spina bifida and anencephaly (SBA). Not since the rubella vaccine became available 30 years ago have we had a comparable opportunity for primary prevention of such common and serious birth defects. The many epidemiologic studies that resulted in the identification of the preventive effect of folic acid is a model for the kind of research that needs to be done to identify the causes of and primary prevention strategies for other birth defects, the leading cause of infant mortality in the United States. An overview of this research will let readers appreciate the contribution of the article by Werler et al,1 which is published in this issue of JAMA.
See also pp 1233 and 1257.
Spina bifida and anencephaly are common, serious