FGF23 and Marchiafava-Bignami disease: Disturbances of mineral metabolism (CKD-MBD) have also been described as risk factors contributing to mortality in patients with CKD [9] and include disorders in serum calcium (Ca), phosphorus (P), parathyroid hormone (PTH), 25-hydroxy vitamin D and fibroblast growth factor 23 (FGF-23) [10].