PTH and Marchiafava-Bignami disease: Altered bone and mineral metabolism in kidney disease is part of a broader systemic disorder defined by the Kidney Disease Improving Global Outcomes (KIDGO) as CKD‐mineral and bone disorder (CKD‐MBD).4 CKD‐MBD is manifested by either one or a combination of: 1) abnormalities of calcium, phosphate, parathyroid hormone (PTH), or vitamin D metabolism; 2) abnormalities of bone turnover, mineralization, volume or strength, and linear growth; and 3) vascular or soft tissue calcification.