Nutrition exerts a pervasive impact on normal and pathological conditions of the nervous system throughout life. Maternal folate supplementation during pregnancy has reduced developmental disorders of the nervous system, but may have also fostered an increase in individuals harboring genetic polymorphisms that compromise folate usage. Such individuals may harbor a lifetime requirement for additional dietary folate, often not met beyond peri/postnatal periods. An increased association of such polymorphisms has been detected in individuals with autism. Prenatal nutritional supplementation may have inadvertently established latent conditions that, in the absence of continued supplementation, may lead to age-related cognitive decline.