PTH and chronic kidney disease: It is defined as “A systemic disorder of mineral and bone metabolism due to chronic kidney disease (CKD) manifested by either one or a combination of the following: abnormalities in calcium, phosphorus, parathyroid hormone (PTH) or vitamin D metabolism, and/or, abnormalities in bone turnover, mineralization, volume, linear growth, or strength, and/or vascular or other soft tissue calcification.” [4].