FGF23 and Marchiafava-Bignami disease: Chronic kidney disease-mineral and bone disorder (CKD-MBD), characterized by deranged metabolism of calcium, phosphate, parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23), and vitamin D; bone abnormalities, formerly known as “renal osteodystrophy”; and vascular calcification, is a well-established complication of CKD [1].