PTH and chronic kidney disease: KDIGO 2017 guidelines mention that the serum calcium, parathyroid hormone (PTH), and phosphate levels should be monitored in every CKD stage, and treatment needs to be based on serial assessments of PTH, calcium, and phosphate levels, considered together [13]. It is worth noting that the optimal PTH range for dialysis patients is two to nine times the upper normal limit, whereas the best range for non-dialysis patients is unknown.