Hypovitaminosis D in Orthopaedic Trauma: Which Guidelines Should Be Followed?

Objective: To evaluate the risk factors for hypovitaminosis D and to determine the baseline vitamin D supplementation associated with normal vitamin D levels at presentation. Design: Prospective observational study. Setting: Level I trauma center. Patients: This study included 259 adult patients undergoing operative treatment for orthopaedic trauma (OTA 11-15, 21-23, 31-34, 41-44, 61-62, 70C, 81-82, 87) between January 1, 2014, and December 31, 2014. Intervention: Prospective, observational study. Main Outcomes: Association of hypovitaminosis D with patient characteristics, injury factors, and vitamin D supplementation. Results: Univariate predictors of hypovitaminosis D included a lack of preinjury supplementation, non-white race, younger age, female sex, non-Medicare insurance, smoking, obesity, Charlson Comorbidity Index,2, and high-energy mechanism. On multivariate analysis, preinjury supplementation was associated with a lower risk (odds ratio: 0.31, 95% confidence interval: 0.15-0.63, P = 0.001) and non-white race was associated with a higher risk (odds ratio: 3.63, 95% confidence interval: 1.58-8.37, P = 0.001) of hypovitaminosis D. Logistic regression analysis found a dose-dependent relationship between vitamin D supplementation and hypovitaminosis D. Each 100-IU increase in vitamin D supplementation was associated with an 8% decrease in the risk of hypovitaminosis D. Conclusions: A lack of preinjury supplementation and non-white race were independently associated with hypovitaminosis D. Baseline supplementation consistent with Endocrine Society guidelines (2000 IU daily) was more effective than that consistent with Institute of Medicine guidelines (400 IU daily) in maintaining 25-hydroxyvitamin D above 30 ng/mL in this population.