FGF23 and Marchiafava-Bignami disease: Chronic renal failure causes the condition named as “Chronic Kidney Disease-Mineral and Bone Disorder” (CKD-MBD) which is characterized by a group of alterations in calcium-phosphorus metabolism, changes in hormones involved in bone homeostasis such as parathyroid hormone (PTH), VD and fibroblast growth factor-23 (FGF-23), anomalies in bone turnover and mineralization, and vascular calcification.