beriberi (bĕrˈēbĕrˈē) [key], deficiency disease occurring when the human body has insufficient amounts of thiamine (vitamin B1). The deficiency may result from improper diet (e.g., ingestion of highly refined grains instead of the whole kernels), from poor absorption of thiamine (as in chronic diarrhea), from conditions which increase the vitamin requirements of the body (e.g., hyperthyroidism, pregnancy, fever), or from poor utilization (as in liver disease). In some instances (e.g., alcoholism) the deficiency arises from a combination of several or of all of these factors. Since thiamine is essential for the proper metabolism of carbohydrate and fat and for the normal functioning of enzymes and nervous tissue, the symptoms of the disorder are primarily those of neurological and gastrointestinal disturbances. In severe cases the heart becomes affected, and the nervous disorder may lead to paralysis and death. The disorder is rarely found in the West, occurring only among alcoholics and other groups who exist on grossly inadequate diets. It is a common malady in parts of Asia where the diet consists mainly of polished white rice. The usual treatment is administering dosages of thiamine.