3. The National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NKF-K/DOQI™) Clinical Practice Guidelines provided recommended target values for serum intact parathyroid hormone (iPTH)(150-300 pg/ml), phosphorus (3.5-5.5 mg/dl), calcium (8.4-9.5 mg/dl) and the calcium-phosphorus product (<55 mg2/dl2). The Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guidelines suggested maintaining serum calcium in the reference range (8.5-10.5 mg/dl), phosphorus (2.7-4.5 mg/dl) and PTH values in the range of two to nine times the upper reference limit (130 - 585 pg/ml) in dialysis patients.