Whether a professional athlete or a weekend warrior, most who compete in sports become injured at some point. The most common sports-related injuries involve strains, sprains or fractures to the ankle, knee or hip. While some of these injuries may put an individual on the bench temporarily, others may be career-ending.
The risk for injury increases for those who are involved in contact sports. Football, for example, has one of the highest rates of injuries, making this one of the most dangerous sports today. Therefore, taking a proactive approach to injury prevention is key to success in this sport.
According to a new study, vitamin D status may play an important role in injury prevention among these athletes. Past research has found that vitamin D deficiency is associated with increased fracture risk, decreased fast twitch muscle fiber size, decreased muscle function and increased musculoskeletal pain. In addition, research suggests vitamin D supplementation decreases muscle fatigue and increases cardiopulmonary exercise capacity.
Despite evidence that supports vitamin D is crucial for athletic performance, up to 80% of National Football league (NFL) players and about 86% of college football players may be vitamin D deficient. This led researchers to evaluate the relationship between vitamin D status and lower limb and core muscle injuries among football athletes.
Participants who joined the 2015 NFL combine and had their vitamin D levels tested were included in the analysis. The NFL combine is a week-long showcase in which college football players perform physical and mental exams in front of NFL coaches, managers and scouts in hopes of moving on to play professionally. A total of 214 athletes met this criteria, and thus were included in the study.
The researchers recorded the participants age, race, BMI, sport’s position and injury type. In addition, the participant’s were evaluated for any physical imbalances or compensatory movements through the use of the Functional Movement Screen (FMS). A higher FMS score is associated with an increased risk of injury. Vitamin D levels of at least 32 ng/ml (80 nmol/l) were considered normal, levels between 20-31 ng/ml (50-77.5 nmol/l) were considered insufficient, and levels below 20 ng/ml (50 nmol/l) were considered deficient.
Here is what the researchers found:
- A total of 59% of the participants had insufficient vitamin D levels, 10% of which were vitamin D deficient.
- 50% of the players experienced a lower extremity muscle strain or core muscle injury.
- Low vitamin D status was associated with injury among the participants (p = 0.03).
- Those with a history of injury experienced significantly lower vitamin D levels than those without an injury (p = 0.01).
- African Americans were significantly more likely to have low vitamin D status (p < 0.01).
- Insufficient vitamin D levels were associated with a 1.86 increased odds of lower limb and core injury (p = 0.03), and a 3.61 increased odds of experiencing a hamstring injury (p < 0.001).
- Low vitamin D status was not independently associated with injury history after accounting for confounding factors (p = 0.07).
The researchers concluded,
“Inadequate vitamin D levels are a widespread finding in athletes at the NFL combine. Players with a history of lower extremity muscle strain and core muscle injury had a higher prevalence of inadequate vitamin D.”
This study was primarily limited by its design. When only evaluating individuals at one point in time, and not including an intervention, the researchers were unable to assess how vitamin D status may impact injury risk and overall athletic performance over time. Nevertheless, these findings add another dynamic to the hundreds of studies that have evaluated the role of vitamin D in athletic performance.
Therefore, the Vitamin D Council recommends athletes supplement with 5,000-10,000 IU/day when they are unable to receive safe, sun exposure to ensure their vitamin D needs are being met.
If you are an athlete and supplement with vitamin D, please consider emailing our team at [email protected] to share your story.
Sturges, M. & Cannell, JJ. Low vitamin D status linked with lower limb muscle strain among NFL athletes. The Vitamin D Council Blog & Newsletter, December, 2017.
Rebolledo, B. et al. The Association of Vitamin D Status in Lower Extremity Muscle Strains and Core Muscle Injuries at the National Football League Combine. Arthroscopy: The Journal of Arthroscopic and Related Surgery. 2017.