Schizophrenia is a devastating and poorly understood disease for which the only accepted therapy is nonspecific antipsychotic and anti-seizure medication. This article summarizes the evidence that certain vitamin deficiencies likely worsen the symptoms of schizophrenia, and the evidence that large doses of certain vitamins could improve the core metabolic abnormalities that predispose some people to develop it; it recounts the history of a controversial vitamin-based therapy for schizophrenia called orthomolecular psychiatry; and it concludes by advocating a process for discovering promising new schizophrenia therapies that involves small, carefully conducted clinical trials of nutrient combinations in appropriately selected patients.