In this book the author applies the physiologic and biochemical developments in calcium metabolism to practical clinical use. The experimental and laboratory findings in both normal and abnormal calcium metabolism are employed as a foundation on which rational calcium therapy in pathologic conditions is based. The literature on this subject has been thoroughly consulted, and the essential principles and opinions are concisely presented. All diseases in which calcium metabolism plays a rôle are considered in detail from both the purely scientific and the clinical point of view. Changes in the second edition of this volume include the relationship between the parathyroid hormone and vitamin D, the significance of phosphatases in the mechanism of ossification and in diseases of the bone, dental caries, the influence of calcium on the pharmacologic action of various drugs and the nature of the action of the parathyroid hormone.