The Relationship Between Serum 25[OH]D Concentration and Orthopaedic Infection: A Case-Control Study

Background: An estimated one in two healthy adults in the United Kingdom suffer from low levels of 25[OH]D. Vitamin D is involved in modulating immune response, but there is less clarity over its role in orthopaedic infection. This study assesses the relationship between serum 25[OH]D concentration and orthopaedic infection. Methods: A total of 205 patients in a tertiary referral centre for orthopaedic infection were included in the study. They were divided into groups based on their infection status, matched by age and gender. Data were statistically analysed to determine presence and direction of relationship. Results: A total of 114 patients had an infection. There was no statistically significant difference in age or gender between the two groups. Mean serum 25[OH]D concentration was 39 nmol/L in the group with infection and 59 nmol/L in the group without an infection (p<0.01). Overall mean serum 25[OH]D concentration was 48 nmol/L. There was a correlation between low serum 25[OH]D concentration and rate of infection (odds ratio, 5.94; 95% confidence interval [CI], 3.24 to 10.92) with a bivariate correlation of -0.338 (p<0.01). Conclusion: This study demonstrates an association between low levels of serum 25[OH]D and increased orthopaedic infection. Orthopaedic inpatients suffered from vitamin D insufficiency, and there was a correlation between higher levels of serum 25[OH]D and lower rates of infection. This suggests that prophylactic supplementation of 25 [OH]D may improve outcomes, and provides a foundation for randomized controlled trials to assess its effectiveness in practice.