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

a method that prepares a mother for natural childbirth by providing education and exercises and nutrition and techniques of breathing and relaxation (with the assistance of the father)

a method that prepares a mother for natural childbirth by providing education and exercises and nutrition and techniques of breathing and relaxation (with the assistance of the father)

a method that prepares a mother for natural childbirth by providing education and exercises and nutrition and techniques of breathing and relaxation (with the assistance of the father)