 - History of rheumatoid arthritis, ankylosing spondylitis, hyperparathyroidism, renal osteodystrophy, moderate to severe inflammatory or autoimmune diseases or newly diagnosed thyroid condition requiring titration of medications stable dose and minor dose modifications of thyroid medications are acceptable. Other exclusionary comorbid conditions include thalassemia, moderate to severe malabsorptive syndromes and HIV. Patients diagnosed with the above conditions or similar comorbid andor inflammatory diseases associated with changes in BMD either from the disease process or the therapy of such conditions during the course of the study will be removed from the study at the point of diagnosis. 