pellagra: a disease caused by deficiency of niacin or tryptophan (or by a defect in the metabolic conversion of tryptophan to niacin); characterized by gastrointestinal disturbances and erythema and nervous or mental disorders; may be caused by malnutrition or alcoholism or other nutritional impairments
avitaminosis: any of several diseases caused by deficiency of one or more vitamins
informer: one who reveals confidential information in return for money