The Effects of Vitamin D Repletion in Vitamin D Deficient Patients With Stage 3 and 4 Chronic Kidney Disease

• To assess whether repletion doses of vitamin D increase 25(OH) vitamin D levels to above 30 ng/mL in a multi-ethnic sample of patients with CKD as a secondary outcome. [ Time Frame: 3 months ] [ Designated as safety issue: No ]
• To assess the effect of vitamin D supplementation on mean systolic blood pressure as measured by ambulatory blood pressure in CKD patients as a secondary outcome. [ Time Frame: 3 months ] [ Designated as safety issue: No ]

A randomized clinical trial to determine if vitamin D repletion in CKD (Chronic Kidney Disease) patients with low vitamin D levels will decrease proteinuria, a marker of kidney damage.

This RCT will enroll 128 subjects, men and women over age of 18, with stage 3-4 CKD from various causes including diabetes and hypertension. Patients will be recruited from the Montefiore Medical Center Nephrology clinics and the Montefiore Medical Center internal medicine clinics and other interested individuals.

Informed consent will be obtained on all subjects. All subjects with meet with one of the investigators who will verbally explain to them the purpose of the study and the alternatives.

Blood and urine tests will be collected to assess for proteinuria, vitamin D levels, serum creatinine, calcium and phosphorus, as well as a urine albumin, calcium and creatinine. These tests will be used for experimental purposes only and will be collected at each study visit over the span of 6 months.

There will be two arms, an arm randomized to 50000IU of ergocalciferol once weekly and a placebo arm for 3 months. For an additional 3 months, all patients will be repleted with Vitamin D via open-label extension, based on their levels after 3 months.

Secondary outcomes include ambulatory blood pressure monitoring, hemoglobin A1c, HOMA-IR.

• Chronic Renal Insufficiency
• Proteinuria

• Drug: Vitamin D
  Vitamin D, ergocalciferol, 50000 IU, weekly for 12 weeks, with open label extension for another 3 months
• Other: Placebo
  Patients randomized to this arm will receive one placebo pill once weekly.

• Experimental: Vitamin D 50000 IU
  Patients randomized to this arm will receive 50,000 IU of ergocalciferol in one unmarked pill once weekly.
  Intervention: Drug: Vitamin D
• Placebo Comparator: Placebo
  Patients randomized to this arm will receive a placebo pill once weekly.
  Intervention: Other: Placebo

Inclusion Criteria:

• Age >18 years
• Ability to provide informed consent
• Chronic kidney disease stage 3 and 4
• On ACE inhibitor or ARB for albuminuria if tolerated
• Assessed during eligibility screen:
• Albuminuria >30 mg/g creatinine
• 25(OH) vitamin D level >12.5 and <75 nmol/L

Exclusion Criteria:

• On vitamin D in past 4 weeks
• Plans to relocate out of New York City in the next 6 months
• 25 (OH) Vitamin D level <12.5 nmol/L
• HIV infection
• History of hypercalcemia or kidney stones
• Serum phosphate >5.5 mg/dl in past 3 months
• Serum calcium >10.0 mg/dl in past 3 months
• SBP >160 DBP >100 at screening visit
• Transplanted organ
• Cancer
• Polycystic kidney disease
• Rapidly deteriorating kidney function with the expectation for initiation of dialysis in less than 6 months