Nitrous oxide is a commonly abused inhalant drug. It is known to precipitate vitamin B12 deficiency when used chronically and acutely, especially in people having marginal vitamin B12 reserve. We are presenting a case of nitrous oxide "whippit" abuse in a thirty-three-year-old male with bizarre behavior and delusions. The patient had low normal levels of vitamin B12 (202 pg/ml), but he had...