pellagra (pəlăgˈrə) [key], deficiency disease due to a lack of niacin (nicotinic acid), one of the components of the B complex vitamins in the diet. Niacin is plentiful in yeast, organ meats, peanuts, and wheat germ. The disease manifests itself in lesions of the skin and mucous membrane, diarrhea and other gastrointestinal symptoms, neurological derangement, and mental confusion. It is most common in areas where the diet consists mainly of corn, which, unlike other grains, lacks niacin as well as the amino acid tryptophan, which the body uses to synthesize the vitamin. Treatment includes large doses of niacin and the institution of a proper diet to prevent recurrences.
See D. A. Roe, A Plague of Corn: A Social History of Pellagra (1973).
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