Orthomolecular medicine focuses on the role of proper nutrition in relation to health. Nutrition comes first in medical diagnoses and treatment and drug treatment is used only for specific indications. Universal recommended dietary allowances of nutrients are seen as inadequate, given the individuality of patients’ genetic disposition and the interaction of the environment.

The healthy diet prescribed by orthomolecular medicine, which eliminates junk foods, refined sugar, and food additives, is often supplemented with relatively large doses of vitamins. Megavitamin therapy, as orthomolecular medicine is sometimes called, has been used to treat a variety of conditions, including severe psychiatric diseases.