Vitamin D Supplementation for the Prevention of Cardiovascular Risk

Study Overview
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Brief Summary
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Hypovitaminosis D is highly prevalent in the general population, particularly in obese individuals. Besides being associated with obesity, vitamin D deficiency seems to be involved in the pathogenesis of insulin resistance and low-grade chronic inflammation. In addition, it has been reported that individuals with low vitamin D levels are at increased risk for cardiovascular diseases. A healthy diet and weight loss are cornerstones in the prevention of cardiovascular diseases. Vitamin D supplementation could increase the beneficial effects of these lifestyle interventions. The purpose of this study is to assess whether vitamin D supplementation in conjunction with a hypocaloric diet improves the cardiometabolic profile of overweight/obese subjects to a greater extent than diet alone.

Official Title
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The Role of Vitamin D Supplementation in the Prevention of Cardiovascular Risk Factors

Conditions
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Obesity, Overweight, Insulin Resistance

Intervention / Treatment
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* Drug: Vitamin D
* Drug: Placebo (for vitamin D)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI≥25 kg/m2 Exclusion Criteria: Diabetes mellitus Chronic kidney disease Liver disease Cholestasis Cancer Chronic bowel disease Primary or secondary hyperparathyroidism Treatment with drugs that may affect insulin sensitivity, weight or calcium/vitamin D metabolism Laxative abuse Changes >10% of usual body weight in the previous 6 months Alcohol or illicit drug abuse Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Vitamin D and Diet<br>Cholecalciferol (vitamin D3) 25,000 I.U./2.5 mL oral solution. 25,000 I.U. (one bottle) per week. Hypocaloric diet | Drug: Vitamin D<br> <br> |
| Placebo Comparator: Placebo & Diet<br>Oral solution mimicking cholecalciferol (vitamin D3) 25,000 I.U./2.5 mL. One bottle per week. Hypocaloric diet | Drug: Placebo (for vitamin D)<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in insulin sensitivity (M value) | Insulin sensitivity will be measured with the hyperinsulinemic euglycemic clamp technique and expressed as M value, calculated from the glucose infusion rate during the last 30 min of the clamp. | Baseline, 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in oral glucose tolerance | Oral glucose tolerance will be assessed with a standard 2-hour oral glucose tolerance test (OGTT). | Baseline, 3 months | 
| Change from baseline in body composition | Body composition will be determined by using dual energy X-ray absorptiometry (DXA). | Baseline, 3 months | 
| Change from baseline in anthropometric parameters | Weight, BMI, waist and hip circumference, waist/hip ratio. | Baseline, 3 months | 
| Change form baseline in systolic and diastolic blood pressure |  | Baseline, 3 months | 
| Change from baseline in phosphocalcic metabolism | Serum vitamin D, PTH and calcium | Baseline, 3 months | 
| Change from baseline in inflammatory markers | Interleukin-6 (IL-6), IL-10, adiponectin, TNF-α, C-reactive protein (CRP) and fibrinogen | Baseline, 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Obesity, Insulin resistance, Vitamin D, Cardiovascular risk factors