Vitamin D Supplementation in Wheelchair Indoor Athletes

Study Overview
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Brief Summary
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There is a high prevalence of vitamin D deficiency in Switzerland. In indoor-athletes as well as wheelchair users, vitamin D deficiency occurs even more often. It is well established that vitamin D deficiency has a negative effect on health. However, vitamin D supplementation in individuals with a vitamin D deficiency has a positive effect on muscle performance. In recently published studies with able-bodied subjects, it has been shown that a normal vitamin D level (>75nmol/L) can only be achieved with a high-dose supplementation of vitamin D. The aim of this study is to examine the effect of vitamin D supplementation on exercise performance in wheelchair athletes with vitamin D deficiency . All participants with a vitamin D deficiency are assigned to the intervention group and treated with 6000 IU of vitamin D3 daily over a period of 12 weeks. All participants who have a normal vitamin D level will receive placebo treatment (control group). The physical performance is measured three times at baseline, after six weeks and 12 weeks. The measurements include a Wingate and a dynamometer test.

Official Title
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Effect of Vitamin D3 Supplementation on Exercise Performance in Wheelchair Athletes.

Conditions
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Vitamin D Deficiency, Spinal Cord Injury, Drug Effects, Dietary Supplements, Physical Education and Training/Methods

Intervention / Treatment
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* Dietary Supplement: Vitamin D
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: swiss elite wheelchair athlete 18 to 60 years male, healthy at least 2x45min sports a week Exclusion Criteria: participation in another study medication which influences performance respiratory and cardiovascular disease daily intake of >400IU Vitamin D parathyroid gland disease kidney insufficiency visit abroad below the 37th parallel latitude during study or shortly before

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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Male

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: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Vitamin D<br>alcohol-based (Ethanol 65%) Vitamin D3 (Vi-De 3®. WILD) solution 6000IU per day. | Dietary Supplement: Vitamin D<br>* Vitamin D3 (Vi-De 3®. WILD) 6000IU daily over a period of 12 weeks.<br>|
| Placebo Comparator: Placebo<br>Same alcohol-based solution (Ethanol 65%) as intervention product but without cholecalciferol | Dietary Supplement: Placebo<br>* alcohol-based solution 1.3ml daily over a period of 12 weeks.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| peak power | peak power measured during wingate test | delta change from pre to 12 weeks post supplementation | 
| maximum torque | maximum torque measured with dynamometer | delta change from pre to 12 weeks post supplementation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Vitamin D serum level | measured with venous blood sample | week 0, 1 day before they start supplementation | 
| Vitamin D serum level | measured with venous blood sample | 12 weeks post supplementation | 
| Count of injuries | DASH questionaire | 12 weeks post supplementation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Vitamin D, Exercise Performance, Wheelchair Athletes, Indoor sports, Wingate, Isokinetic Dynamometer