Dietary Supplements, Drug Effects, Physical Education and Training/Methods, Spinal Cord Injury, Vitamin D Deficiency
Conditions
Keywords
Vitamin D, Exercise Performance, Wheelchair Athletes, Indoor sports, Wingate, Isokinetic Dynamometer
Brief summary
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.
Interventions
Vitamin D3 (Vi-De 3®. WILD) 6000IU daily over a period of 12 weeks.
alcohol-based solution 1.3ml daily over a period of 12 weeks.
Sponsors
Study design
Eligibility
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| peak power | delta change from pre to 12 weeks post supplementation | peak power measured during wingate test |
| maximum torque | delta change from pre to 12 weeks post supplementation | maximum torque measured with dynamometer |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Vitamin D serum level | week 0, 1 day before they start supplementation | measured with venous blood sample |
| Count of injuries | 12 weeks post supplementation | DASH questionaire |
Other
| Measure | Time frame | Description |
|---|---|---|
| Heart rate | week 0, 1 day before they start supplementation | Peak heart rate measured during wingate test |
| blood lactate concentration | week 0, 1 day before they start supplementation | before, during and after wingate test |
Countries
Switzerland