Vitamin D metabolism and regulation of calciumphosphorus homeostasis in patients with chronic kidney disease

Chronic kidney disease (CKD) is associated with significant disturbances in mineral and vitamin D metabolism, leading to the development of CKD-related mineral and bone disorders (CKD-MBD) and an increased risk of cardiovascular complications, fractures, and mortality. This paper reviews the mechanisms of calcium-phosphorus homeostasis and vitamin D metabolism regulation in CKD, focusing also on the roles of parathyroid hormone (PTH), fibroblast growth factor-23 (FGF-23) and the Klotho protein. Modern approaches to laboratory diagnostics and target mineral parameters in CKD patients are discussed, as well as the potential use of novel biomarkers, such as the 24,25(OH) 2 D/25(OH)D ratio (VMR) and 1,24,25(OH) 3 D/1,25(OH) 2 D ratio (1,25VMR). This review highlights the need for further research to optimize the diagnosis and treatment of mineral disturbances in CKD patients.