Paricalcitol Versus Calcitriol for Efficacy and Safety in Stage 3/4 Chronic Kidney Disease (CKD) With Secondary Hyperparathyroidism (SHPT)

Inclusion Criteria 1. Age \>18; Able to give informed consent 2. Chronic kidney disease, and estimated GFR 15 to 60 ml/min using the abbreviated MDRD equation 3. intact PTH (iPTH) \>120 pg/ml at baseline 4. albumin corrected calcium \> 8.5 mg/dL to \< 10.0 mg/dL at baseline 5. Phosphorus \< 4.6 mg/dL at baseline 6. If on a phosphorus binder; no change in dose within the 4 weeks prior to screening Exclusion Criteria 1. Receiving any active form of vitamin D within 4 weeks prior to screening (calcitriol, doxercalciferol; paricalcitol; alfacalcidol) 2. Receiving \>50,000 IU per month of ergocalciferol or \> 1000 IU of cholecalciferol per day within the previous 30 days. 3. history of primary HPT 4. On prednisone \> 30 days within the previous 6 months 5. receiving bisphosphonates or calcitonin within the previous 12 months 6. Non-elective hospitalization within the previous 30 days. 7. Expected to initiate dialysis or receive a kidney transplant within the next 6 mo. 8. History of renal or other organ transplant 9. History of parathyroidectomy or previous diagnosis of primary hyperparathyroidism 10. Receiving cinacalcet within 4 weeks prior to screening. 11. An active drug/alcohol dependence or abuse history 12. History of non-compliance with visits or medications that preclude study compliance in the opinion of the investigator 13. Pregnant, or able to become pregnant and unwilling to use a birth control method considered reliable by the principal investigator