Date of Graduation


Document Type


Degree Name

Master of Athletic Training (MAT)

Degree Level



Health, Human Performance and Recreation


Brendon McDermott

Committee Member

Lesley Vandermark

Second Committee Member

Casey Wagner

Third Committee Member

Gary Wilkerson


Injury, Musculoskeletal, Prediction, Vitamin D


Context: Pre-season testing that includes the analysis of micronutrient serum levels in the blood has become a routine part of pre-participation examinations in collegiate football. Objective: Assess the predictability of vitamin D and iron serum levels as indicators of future injury during a subsequent competitive season for lower extremity sprains, strains, and fractures. Additionally, determine the effectiveness of vitamin D supplementation on increasing serum 25(OH)D levels and preventing injury. Design: Cohort Study. Setting: National Collegiate Athletic Association Division I football program. Participants: Football athletes (n=349) who underwent pre-participation examinations and participated in at least one of three competitive football seasons. Main Outcome Measure(s): Vitamin D and Iron serum levels collected during pre-season testing and injury occurrence of the lower extremity or core was analyzed to determine if a predictive association existed. A vitamin D serum level cut-point for high-risk or low-risk athletes was established using a receiver operator characteristic analysis (ROC) for various injury associations including all injuries, fractures, and muscle strains. Cross-tabulation analysis produced sensitivity, specificity, positive and negative likelihood ratios, and odds ratios for each cut-point. Backwards stepwise logistic regression was used to determine the best combination of injury risk factors. Individuals supplemented with vitamin D were analyzed using a paired-samples T-Test to determine if supplementation procedures were effective. Results: Muscular injuries were significantly predicted by low vitamin D levels (<23.15 ng/mL; OR=3.042; 90% CI [1.426, 6.486], p=0.019) high game exposure (OR=2.636; 90% CI [1.208, 5.753], p=0.036), previous injury (OR=3.390; 90% CI [1.546,7.431], p=0.010). Based on a three-factor prediction model, athletes with two or more risk factors were at an increased risk of injury with an odds ratio of 6.000 (90% CI [2.639, 13.642], p=0.001). Vitamin D supplementation increased mean pre-season levels by 32.206 15.52 (p<.001). Conclusion: Use of a model with multiple risk factors can help identify athletes who are at risk for injury based on both intrinsic and extrinsic factors. The modifiable factor of vitamin D status may help athletic trainers to decrease injury risk in those with low serum 25(OH)D levels through a short-term supplementation program.