PTH and chronic kidney disease: The clinical practice guideline for CKD-mineral and bone disorder (CKD-MBD) from Kidney Disease: Improving Global Outcomes (KDIGO) in 2010 [14] suggests maintaining PTH level in the range of approximately 2 to 9 times the upper normal limit for assay, which is the same with a renewed guideline in 2017 considering better survival [15].