Researchers and physicians in the fields of molecular genetics, neural development, obstetrics and gynecology, genetic and reproductive toxicology, pediatrics, cell biology and anatomy, nutrition sciences, and other fields offer a critical evaluation of the role of folate in human health and development. 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 folate1s role in vascular disease in women. Also covered are genes and neural tube development, folate receptor polymorphism and the risk of neural defects, abnormal DNA synthesis and methylation with folate/methyl insufficiency, and folic acid and homocysteine as risk factors for neural-tube defects.