This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'All are causes of osteoporosis except - \nSelect and explain. \nA. Old age, B. Chronic heparin therapy, C. Hypothyroidism, D. Thyrotoxicosis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Osteoporosis \n\nOsteoporosis is a disease characterized by increased porosity of the skeleton resulting from reduced mineral\xa0mass.\n\nImportant causes of osteoporosis\n\tPrimary\n\tPostmenopausal\n\tSenile\n\tIdiopathic\n\nSecondary\nEndocrine disorders\n\nHyperparathyroidism\nThyrotoxicosis\nHypogonadism\nCushing syndrome\nDM type 1\nAddison diseases\n\nNeoplasia\nMultiple myeloma\nCarcinomatosis\n\nGastrointestinal\nMalnutrition and malabsorption\nVit. C, D deficiencies\n\nImportant drugs\nHeparin\nGlucocorticoids\nLithium\nCyclosporin\nGn RH agonists\nAnticonvulsants\nAlcohol\nOthers\nOsteogenesis imperfecta\nImmobilization\nHomocystinuria\nRheumatological disease', 'role': 'assistant'}]