Exclusion Criteria: Use of agents affecting bone metabolism, use of more than one biologic agent for inflammatory disease, history of bone disease (except osteoporosis), low vitamin D level (one can enter the trial after vitamin D levels are corrected), abnormalities of blood calcium, an underactive or overactive thyroid condition that is not treated and stable, Addison's disease, any abnormality of the parathyroid glands (the glands that control blood calcium), currently pregnant or planning a pregnancy, currently breast feeding, and other criteria may apply.