FGF23 and chronic kidney disease: In phase 2, 45 patients were followed up as a prospective cohort study for 24 weeks to further explore the effect of cinacalcet on CKD-MBD parameters including laboratory markers, such as calcium, phosphate, iPTH, FGF-23, BAP, vitamin D, 1,25 vitamin D, TRAP5b; parathyroid gland size; and vascular calcification at 24 week-follow up and 12 weeks after discontinuing cinacalcet.