An authoritative panel of basic and clinical researchers critically reviews the latest findings on the role of folate in human development, health, and disease. Specific areas addressed include folate metabolism in zinc or copper deficiencies, choline and folate in development, animal models of folate-related birth defects, developmental toxicants potentially acting via folate perturbation, and folate's role in vascular disease in women. There are also cutting-edge discussions of genes and neural tube development, folate receptor polymorphism and the risk for neural defects, abnormal DNA synthesis and methylation with folate/methyl insufficiency, and folic acid and homocysteine as risk factors for neural tube defects.