Dec 21, 2017Vitamin D and Injury Rates
Athletic trainers have likely heard a lot about the correlation between vitamin D deficiencies and injury risk. At the University of Arkansas, our athletic training faculty recently teamed up with our sports medicine staff to dig into this topic for ourselves.
The sports medicine staff has been drawing preseason blood samples for years to assess athletes’ overall health, immune function, and organ function as a standard screening. What typically did not occur with these data, however, was seeing if the information could be more valuable than the standard.
So, the next step was to team up with the athletic training faculty to run a brief analysis of documented injuries combined with preseason vitamin D levels. First, an Excel spreadsheet was created with rows for each player and columns for documented injuries (specific to type and location) for the 2015-16 competitive seasons.
Then, provided de-identified data, a researcher conducted a brief analysis in a statistical software program. The analysis itself took about 15 minutes. Our research questions included:
- Is preseason vitamin D value related to fracture risk?
- Is preseason vitamin D value related to overall lower extremity or core injury (sprain, strain, or fracture)?
- Is preseason vitamin D value related to lower extremity or core muscle injury?
What we found was interesting. Preseason vitamin D levels were not associated with fracture risk but were mildly associated with lower extremity or core sprain or strain injury. Football players were 1.4 times more likely to sustain a sprain or strain injury during the season if their preseason vitamin D level was less than or equal to 26 nanograms per milliliter (ng/mL).
When we split out muscle injury only, we found a significant association. Players with values less than or equal to 23.2 ng/mL were 2.4 times more likely to suffer a muscle strain during the season than players who had greater values. This association was demonstrated despite a normal supplementation regimen when measured values were less than 40 ng/mL at preseason. The supplementation plan was implemented secondary to the known fracture risk factors associated with low vitamin D levels. However, our numbers — as well as some recent evidence — suggest that lower concentrations of vitamin D in the blood reflect inflated injury risk in other forms. Either way, our analysis provides evidence-based support for the current practice of recommending supplementation for football players with low vitamin D values.
In today’s evidence-based world of athletic training, clinicians should continue to work with researchers to provide support for current practices. Further, this continued practice can help raise important research questions that advance scientific support for things like injury prevention, treatment effectiveness, clinical outcomes, and augmented patient safety. Advanced advocacy for data sharing among larger sample sizes is recommended, as well, because this would help strengthen associations between different variables. Athletic trainers are encouraged to continue with analyses of data they are collecting on a routine basis in their current practices.