This study will assess the effects of vitamin D3 supplementation (cholecalciferol; 2000 IU daily) on serum calcium levels, circulating vitamin D levels, and markers of kidney disease and cardiovascular risk among people with diabetes mellitus and early kidney disease. Eligibility criteria include type 2 diabetes and stage 1-2 chronic kidney disease, defined by a urine albumin-creatinine ratio 30-300 mg/g and an estimated glomerular filtration rate ≥ 60 mL/min. Participants will be randomly assigned to treatment with vitamin D3 or placebo, each taken by mouth once daily for a study duration of one year. Study medications will be added to standard treatment, including an angiotensin converting enzyme inhibitor and/or angiotensin II receptor blocker. We hypothesise that vitamin D3, compared with placebo: Is well-tolerated and safe among people with diabetes and kidney disease;Results in adequate attained circulating vitamin D levels; andPositively affects markers of kidney disease and cardiovascular risk.

Official Title

Randomised Controlled Trial of Vitamin D3 in Diabetic Kidney Disease.

Conditions

  • Diabetes Mellitus
  • Chronic Kidney Disease
  • Diabetic Kidney Disease

Study Type

Interventional

Study Design

Treatment, Randomised, Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Placebo Control, Parallel Assignment.

Further Details

Primary Outcome Measures:

  • Change in urine albumin excretion
    [Time Frame: One year]
    [Designated as safety issue: No]

Secondary Outcome Measures:

  • Change in serum calcium concentration 
    [Time Frame: 3 months – 1 year]
    [Designated as safety issue: Yes]
  • Change in serum 25-hydroxyvitamin D concentration
    [Time Frame: 3 months – 1 year] 
    [Designated as safety issue: No]
  • Change in 24-hour ambulatory blood pressure
    [Time Frame: 3 months – 1 year]
    [Designated as safety issue: No]
  • Change in plasma lipids and lipoproteins
    [Time Frame: 3 months – 1 year]
    [Designated as safety issue: No]
  • Change in circulating inflammatory proteins
    [Time Frame: 3 months – 1 year]
    [Designated as safety issue: No]
  • Changes in circulating markers of mineral metabolism and insulin sensitivity
    [Time Frame: 3 months – 1 year]
    [Designated as safety issue: No]

Study Start

December 2007

Eligibility & Criteria

  • Ages Eligible for Study: 18 Years and older
  • Genders Eligible for Study: Both
  • Accepts Healthy Volunteers: No

Inclusion Criteria:

  • Clinical diagnosis of type 2 diabetes mellitus
  • Urine albumin-creatinine ratio 30-300 mg/g
  • Estimated glomerular filtration rate greater than or equal to 60 mL/min
  • Treatment with angiotensin converting enzyme inhibitor and/or angiotensin II receptor blocker for greater than or equal to 6 months, with a stable dose for greater than or equal to 3 months
  • Blood pressure less than 140/90 (assessed while taking medications)
  • Hemoglobin A1c less than 9% (assessed while taking medications)

Exclusion Criteria:

  • Prior dialysis or kidney transplantation
  • Known cause of albuminuria other than diabetes
  • Planning to leave the area within 12 months
  • Life expectancy less than 12 months
  • Participation in another clinical trial within 6 months
  • Osteoporosis or other established indication for vitamin D therapy
  • Vitamin D3 supplement intake greater than 400 IU/day at screening visit
  • History of nephrolithiasis
  • Serum calcium greater than 10.2 mg/dL
  • Dementia, not fluent in English, or unable to provide informed consent without proxy respondent
  • Incontinent of urine
  • Failure to take greater than or equal to 80% of placebo pills during study run-in 

Total Enrolment

Contact Details

Ian H de Boer, MD, MS     
(206) 616-5403     
deboer@u.washington.edu 

Location:

University of Washington
Seattle, Washington
United States, 98195