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

Abstract

(1) 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; (2) 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; (3) 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; (4) 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.

miR‑34a alleviates spinal cord injury via TLR4 signaling by inhibiting HMGB‑1

“…Spinal cord injury (SCI) is one of the most common injuries that requires spinal surgery (1). SCI is often caused by traffic accidents, falls, construction accidents and sports injuries (1). The incidence of SCI has increased with urban and transportation development (1).…”

“…SCI is often caused by traffic accidents, falls, construction accidents and sports injuries (1). The incidence of SCI has increased with urban and transportation development (1). Recent epidemiological studies have suggested that 11,000 new cases of SCI are reported each year in the USA (1,2).…”

Effectiveness of two vitamin D3 repletion protocols on the vitamin D status of adults with a recent spinal cord injury undergoing inpatient rehabilitation: a prospective case series

“…Our findings indicate that administration of either of the two regimens for at least 1 month did not cause any adverse effects. Although we cannot exclude that deleterious effects may occur over time, studies done in adults with chronic SCI failed to report any toxicity with larger doses and over longer periods than those tested in this study [13,14].…”

“…Although people with SCI are at high risk of impaired vitamin D status, the Endocrine Society clinical practice guidelines on vitamin D have not included explicit population-specific recommendations [11]. Furthermore, only a few repletion protocols have been tested in adults with SCI with varying degrees of improvement [12][13][14][15]. However, most of these studies have been performed in adults with chronic SCI and information regarding vitamin D supplementation strategies shortly after an initial SCI is lacking.…”

Importance of Vitamin D in Athletes and Exercise; A mini review

“…At the same time, also concluded that the correlation of injuries to vitamin D levels in human body is unclear [19]. Another study evaluated the effect of vitamin D in wheelchair injured athletes and the results support the unclear association of vitamin D with injuries [21]. Nevertheless, a study evaluated Vitamin D status and biomarkers of inflammation in runners and supported a possible link between decreased vitamin D status and one particular marker of inflammation [46].…”