This volume is designed to provide an understanding of current and potential therapies for osteoporosis. The opening chapter introduces the cells of bone and their interactions. Several following chapters describe factors affecting bone including systemic hormones with significant effects on bone, and local mediators including growth factors, prostaglandins, cytokines and chemokines. Topics that have commanded particular attention recently are calcium, FGF-23, nervous system bone interactions. Drugs that cause bone loss provide important information on mechanism as well as therapeutic considerations. An overview of the genetics of bone disorders and a discussion of the pathophysiology of osteoporosis establish the clinical context. The final chapters discuss current and potential osteoporosis treatments.