Vitamin D and Calcium Homeostasis for Prevention of Type 2 Diabetes

Study Overview
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Brief Summary
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The purpose of the randomized trial is to quantify the effect of vitamin D and calcium supplementation on beta-cell function, insulin sensitivity, glucose tolerance and systemic inflammation and other cardiometabolic outcomes in ambulatory adults at high risk for type 2 diabetes.

Detailed Description
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There is animal and human observational evidence to suggest that vitamin D and calcium are important in modifying t2DM risk but there are critical gaps in our knowledge about the clinical magnitude of the association with t2DM and potential mechanisms in humans. We are conducting a randomized trial to quantify the effect of vitamin D and calcium supplementation on beta-cell function, insulin sensitivity, glucose tolerance and systemic inflammation and other cardiometabolic outcomes in ambulatory adults at high risk for t2DM. We anticipate that the research proposed in this application is significant because it will provide the basis for defining feasible nutritional interventions that promotes prevention of t2DM. Based on the results of the proposed studies and future work in this area, vitamin D and calcium supplementation can assume an important role in the treatment of t2DM and in the prevention of the disease in the 41 million Americans who are at risk of developing t2DM.

Official Title
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Vitamin D and Calcium Homeostasis for Prevention of Type 2 Diabetes

Conditions
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Glucose Intolerance, Type 2 Diabetes Mellitus, Metabolic Syndrome

Intervention / Treatment
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* Drug: Vitamin D3 2,000 IU orally once daily
* Drug: Calcium Carbonate 400 mg orally twice daily
* Drug: Vitamin D3-Placebo
* Drug: Calcium-Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Ethnicity: all ethnic groups Gender: men and women Age Lower age limit: 40 years inclusive Upper age limit: NONE BMI Lower BMI limit: 25 inclusive Upper BMI limit: 40 inclusive Glucose Intolerance / Mild Diabetes defined as Fasting glucose ≥100 mg/dl OR 2-hr glucose after OGTT ≥140 mg/dl OR 5.8 ≤ Hemoglobin A1c ≤ 7 Major Exclusion Criteria: Diabetes requiring pharmacotherapy Smoking Hyperparathyroidism Hypercalcemia (Calcium > 10.5 mg/dl) Kidney stone Pregnancy

Ages Eligible for Study
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Minimum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: 1<br>Vitamin D3 2,000 IU daily plus Calcium Carbonate 400 mg twice daily | Drug: Vitamin D3 2,000 IU orally once daily<br>* Vitamin D3 2,000 IU orally once daily<br>Drug: Calcium Carbonate 400 mg orally twice daily<br>* Calcium Carbonate 400 mg orally twice daily<br>|
| Other: 2<br>Vitamin D3 2,000 IU daily plus Calcium-Placebo twice daily | Drug: Vitamin D3 2,000 IU orally once daily<br>* Vitamin D3 2,000 IU orally once daily<br>Drug: Calcium-Placebo<br>* Calcium-Placebo<br>|
| Other: 3<br>Vitamin D3-Placebo plus Calcium Carbonate 400 mg twice daily | Drug: Calcium Carbonate 400 mg orally twice daily<br>* Calcium Carbonate 400 mg orally twice daily<br>Drug: Vitamin D3-Placebo<br>* Vitamin D3-Placebo<br>|
| Other: 4<br>Vitamin D3-Placebo plus Calcium-Placebo | Drug: Vitamin D3-Placebo<br>* Vitamin D3-Placebo<br>Drug: Calcium-Placebo<br>* Calcium-Placebo<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Chang in Disposition Index, a Measure of Beta Cell Function | Range is 0 to infinity Lower is better. | baseline and 4 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Hemoglobin A1c | This outcome measures change in Hemoglobin A1c, a measure of glycemia | Baseline to 4 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Glucose intolerance, Type 2 diabetes mellitus, Metabolic syndrome