Study of Teriparatide (FORTEO) to Treat Adults With Osteogenesis Imperfecta

Inclusion Criteria: * Previous established diagnosis of Osteogenesis Imperfecta AND * \> 2 previous adult fractures, AND/OR * BMD at lumbar spine, femoral neck or total hip T score \< -2.0 Exclusion Criteria: * Open epiphyses. * History of external beam radiation to the skeleton. * Pagets disease. * Bone metastases or skeletal malignancies. * Total lifetime exposure to any antiresorptive medication \< 90 days (Primary Inclusion). * Treatment with any antiresorptive medication 12 months proceeding enrollment - (Secondary Inclusion). * Women with OI who are pregnant or unwilling to use 1 form of contraception. * Vitamin D insufficiency (25-hydroxyvitamin D \<15ng/ml)