Compare the Efficacy of Cinacalcet vs Traditional Vitamin D for Secondary Hyperparathyroidism (SHPT) Among Subjects Undergoing Hemodialysis

Inclusion Criteria: * Age ≥ 18 years at screening * Treated with maintenance hemodialysis 3 times a week for ≥ 3 months prior to screening * Informed consent provided by the study candidate * For subjects NOT receiving cinacalcet and/or vitamin D therapy for SHPT within 60 days prior to enrollment: Plasma PTH levels ≥ 450 pg/mL (50 pmol/L) during screening, as obtained from the central laboratory and, Serum corrected total calcium ≥ 8.4 mg/dL (2.1 mmol/L) and \< 10.2 mg/dL (2.55 mmol/L) during screening, as obtained from the central laboratory Exclusion Criteria: * Parathyroidectomy in the 12 weeks before the date of informed consent * History of seizure within 12 weeks prior to randomization * Scheduled for kidney transplant * Parathyroidectomy anticipated within the next 6 months * Liver function tests \> than 2 x the Upper Limit of Normal * Prior use of bisphosphonates, or expected to receive bisphosphonates during the trial * Subject has previously enrolled in this study * General * Other investigational procedures are excluded * Currently enrolled in another investigational device or drug study, or less than 30 days since ending another investigational device or drug study(s), or receiving other investigational agent(s) * Subject (male or female) is not willing to use highly effective contraception during treatment and for at least one month (women) and 3 months (men) after the end of treatment * Subject is pregnant or breast feeding, or planning to become pregnant during study or within 1 month after the end of treatment Male subject with a pregnant partner who is not willing to use a condom during treatment and for at least 1 month after the end of treatment * Subject has known sensitivity or intolerance to any of the protocol required therapies * Subject will not be available for protocol-required study visits, to the best of the subject and investigator's knowledge * Subject has any kind of disorder that, in the opinion of the investigator, may compromise the ability of the subject to give written informed consent and/or to comply with all required study procedures