Calcium and Phosphate Disorders: Core Curriculum 2024

Abstract

Maintaining normal calcium and phosphate homeostasis is essential for optimal cellular, metabolic, and organ function. Parathyroid hormone, fibroblast growth factor 23, and 1,25-dihydroxyvitamin D regulate calcium and phosphate homeostasis via multiple interlinked feedback loops, receptors, ion channels, and transporters. Following an initial overview of the stimuli and effects of the different hormonal regulators, this installment of AJKD's Core Curriculum in Nephrology reviews the physiology and pathophysiology of calcium and phosphate disorders through the lens of a series of illustrative cases. The cases span clinical conundrums commonly encountered by nephrologists in their daily clinical practice and other less common disorders. Some of the cases present in the outpatient clinic setting and others in the inpatient hospital setting. Patients with normal kidney function, chronic kidney disease, kidney failure, and acute kidney injury are all represented. Some of the disorders are iatrogenic, and some are due to native disease. All demonstrate key aspects of pathophysiology that are essential knowledge for nephrology clinicians of all career stages.