Preoperative vitamin D deficiency and postoperative delirium risk: multicenter retrospective study.

Background: To assess the impact of preoperative vitamin D deficiency (VDD) on the risk of postoperative delirium (POD) in patients undergoing musculoskeletal surgery. Methods: This cohort study utilized the TriNetX Healthcare Commercial Organizations database. We included patients aged 50 years or older who underwent musculoskeletal surgery requiring hospital admission. Patients were categorized according to their preoperative vitamin D levels into three groups: deficient (≤20 ng/mL), insufficient (21-29 ng/mL), and sufficient (≥30 ng/mL). The primary outcome was POD within 30 days of surgery. Secondary outcomes included risks of surgical site infections, emergency department (ED) visits, and intensive care unit (ICU) admissions. Risk factors for POD were assessed using multivariate logistic regression analysis. Results: After matching, 6,218 pairs of vitamin D-deficient and sufficient patients were compared. VDD was related to a significantly higher risk of POD [1.0% vs. 0.5%; odds ratio (OR): 2.18, 95% confidence interval (CI): 1.41-3.36, Conclusion: Individuals with VDD experienced a higher risk of POD, suggesting the potential benefits of preoperative vitamin D screening and supplementation as a strategy to improve outcomes in surgical patients. While our findings highlight the potential benefit of vitamin D assessment and optimization before surgery, the retrospective design limits the ability to draw causal inferences. Prospective interventional studies are warranted to determine whether treating VDD can meaningfully lower the risk of POD.