The purpose of this study is to determine if treatment with paricalcitol, an active form of vitamin D, has beneficial effects on metabolic abnormalities in people with stage 3-4 Chronic Kidney Disease (CKD).

Persons with chronic kidney disease (CKD) are at markedly increased risk of death, particularly from cardiovascular disease (CVD). A number of metabolic abnormalities may contribute to adverse health outcomes in CKD, including glucose intolerance, altered immune cell function, and oxidative stress. Each of these metabolic stressors is a known complication of CKD. Since these metabolic abnormalities are also known to contribute to the pathogenesis of cardiovascular disease, they are important potential therapeutic targets in CKD.

This study will test whether oral paricalcitol, an active form of vitamin D, will improve glucose tolerance, immune cell function, and reduce oxidative stress in people with stage 3-4 chronic kidney disease.

Inclusion Criteria:

• Estimated glomerular filtration rate of 15-59 mL/min/1.73m2
• Fasting glucose 100-125 mg/dL
• 18 years and older

Exclusion Criteria:

• Diagnosed with diabetes mellitus
• Use of diabetes medications (insulin or oral hypoglycemics)
• Prior dialysis or transplantation
• Planning to leave the area within 6 months
• Participation in another clinical trial within 30 days
• Treatment with paricalcitol, calcitriol, or corticosteroids in the preceding 8 weeks
• Serum calcium more than 10.2 mg/dL
• Pregnancy or breast-feeding
• Change in dose (within 8 weeks) of Fibrates, Niacin, ACE inhibitors, Angiotensin receptor blockers, Thiazide diuretics, Beta-blockers, Cholecalciferol or Ergocalciferol
• Incontinent of urine
• Cancer (other than skin cancer) within 5 years
• Tuberculosis
• Sarcoidosis