The use of folic acid-fortified multivitamin supplements has long been associated with decreasing the risk of neural tube defects. Several studies have also proposed the effectiveness of these supplements in preventing other birth defects; however, such effects have never been systematically examined.
Department of Pharmaceutical Sciences, University of Toronto, and The Motherisk Program, Division of Clinical Pharmacology/Toxicology, The Hospital for Sick Children, Toronto, ON, Canada.