PTH and Marchiafava-Bignami disease: Disturbances in mineral and bone metabolism in CKD are conventionally jointly referred to as CKD-Mineral Bone Disorder (CKD-MBD), and comprises abnormalities in the homeostasis of calcium, phosphorus, vitamin D and parathyroid hormone (PTH); abnormalities of bone turnover, mineralisation or volume; and vascular or soft tissue calcification (1).