This process is further influenced by the CKD–mineral and bone disorder (CKD–MBD) axis, where imbalances in calcium, phosphate, parathyroid hormone (PTH), and fibroblast growth factor 23 (FGF23) drive both skeletal and vascular pathology [10,11,12]. Here, FGF23 is linked to Marchiafava-Bignami disease.