<prompt> All of the following are the known causes of osteoporosis except :FluorosisHypogonadismHypehyroidismHyperparathyroidism  <response>: Answer is A Fluorosis: Fluorosis is associated with Osteosclerosis and not with osteoporosis. Hypogonodism, Hypehyrodism and Hyperparathyrodism are all known causes for osteoporosis. 