Randomized Controlled Trial of Vitamin D3 in Diabetic Kidney Disease

Study Overview
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Brief Summary
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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 hypothesize that vitamin D3, compared with placebo: (1) is well-tolerated and safe among people with diabetes and kidney disease; (2) results in adequate attained circulating vitamin D levels; and (3) positively affects markers of kidney disease and cardiovascular risk.

Official Title
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Randomized Controlled Trial of Vitamin D3 in Diabetic Kidney Disease

Conditions
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Diabetes Mellitus, Chronic Kidney Disease, Diabetic Kidney Disease

Intervention / Treatment
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* Dietary Supplement: Cholecalciferol
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Clinical diagnosis of type 2 diabetes mellitus Urine albumin-creatinine ratio 30-1000 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) 25-hydroxyvitamin D less than 30 ng/mL 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

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cholecalciferol<br> | Dietary Supplement: Cholecalciferol<br>* 2000 IU by mouth daily for one year<br>|
| Placebo Comparator: Placebo<br> | Dietary Supplement: Placebo<br>* One softgel daily for one year<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Urine Albumin Excretion | Albumin and creatinine concentrations were measured in 24hr urine collections at baseline, 3 months after randomization, and one year after randomization. We analyzed the difference in log-transformed albumin-creatinine ratio (ACR, mg/g) after randomization (3 months and one year, analyzed together with all available data included) compared with baseline, by treatment assignment. Results are transformed to present percent difference in urine ACR. | Baseline, 3 months, and one year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Diabetes mellitus, Type 2 diabetes, Chronic kidney disease, Diabetic kidney disease, Microalbuminuria, Albuminuria, Vitamin D, Cholecalciferol, Kidney, Renal, Cardiovascular, Clinical trial, Placebo