PATIENT SELECTION - Patients with biopsy proven advanced prostate cancer, no known prior clinical or radiographic history of osteoporosis, minimum of 1 year of hormonal therapy in arms 2, 3, 4, 5 and 6, and an ability and willingness to give informed consent. Exclusion criteria - Patients with known bone disorders other than metastatic disease such as hyperparathyroidism, Paget's disease, renal osteodystrophy, and documented osteomalacia as well as osteoporosis, patients who have received a bisphosphonate, systemic fluoride, pharmacological doses of calcium (less than 1500 mg/day) or Vitamin D (less than 1000 IU/day), or calcitonin, patients with known abnormal thyroid function, and patients with marked renal impairment (creatinine less than 2.0 X normal).