Spinal Cord Injury wheelchair athletes helped by 12 weeks of Vitamin D – Sept 2016

Effect of 12-Week Vitamin D Supplementation on 25[OH]D Status and Performance in Athletes with a Spinal Cord Injury.

Nutrients. 2016 Sep 22;8(10). pii: E586. doi: 10.3390/nu8100586.

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Flueck JL1, Schlaepfer MW2, Perret C3.

• 1 Institute of Sports Medicine, Swiss Paraplegic Centre Nottwil, Nottwil 6207, Switzerland. joelle.flueck at paraplegie.ch.
• 2 Institute of Human Movement Sciences and Sport, ETH Zurich, Zurich 8092, Switzerland. maxwschlaepfer at gmail.com.
• 3 Institute of Sports Medicine, Swiss Paraplegic Centre Nottwil, Nottwil 6207, Switzerland. claudio.perret at paraplegie.ch.

BACKGROUND: studies with able-bodied athletes showed that performance might possibly be influenced by vitamin D status. Vitamin D seems to have a direct impact on neuromuscular function by docking on vitamin D receptors in the muscle tissue. Additionally, a high prevalence of vitamin D deficiency was shown not only in infants and in the elderly but also in healthy adults and spinal cord injured individuals. Therefore, the aim of our study was to investigate whether a vitamin D dose of 6000 IU daily over 12 weeks would be sufficient to increase vitamin D status in indoor wheelchair athletes to a normal or optimal vitamin D level and whether vitamin D deficiency is associated with an impairment in muscle performance in these individuals;

METHODS: vitamin D status was assessed in indoor elite wheelchair athletes in order to have a baseline measurement. If vitamin D status was below 75 nmol/L, athletes were supplemented with 6000 IU of vitamin D daily over 12 weeks. A vitamin D status over 75 nmol/L was supplemented with a placebo supplement. Vitamin D status, as well as a Wingate test and an isokinetic dynamometer test, were performed at baseline and after six and 12 weeks;

RESULTS: 20 indoor elite wheelchair athletes participated in this double-blind study. All of these athletes showed an insufficient vitamin D status at baseline and were, therefore, supplemented with vitamin D. All athletes increased vitamin D status significantly over 12 weeks and reached an optimal level. Wingate performance was not significantly increased. Isokinetic dynamometer strength was significantly increased but only in the non-dominant arm in isometric and concentric elbow flexion;

CONCLUSION: a dose of 6000 IU of vitamin D daily over a duration of 12 weeks seems to be sufficient to increase vitamin D status to an optimal level in indoor wheelchair athletes. It remains unclear, whether upper body performance or muscle strength and vitamin D status are associated with each other.

PMID: 27669288 PMCID: PMC5083975 DOI: 10.3390/nu8100586

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From PDF

• “Nineteen out of twenty athletes reached an optimal vitamin D status (100 to 220 nmol/L) after six weeks, and no one showed a toxic level (>375 nmol/L).”