Background: Vitamin D is essential for bone remodeling, muscle function, and immune regulation. Its deficiency is common among patients undergoing total knee arthroplasty (TKA) and has been linked to delayed recovery, higher complication rates, and an increased risk of periprosthetic joint infections (PJIs). However, the impact of perioperative vitamin D supplementation on TKA outcomes remains unclear. Purpose: To evaluate if perioperative vitamin D supplementation would correct hypovitaminosis D; improve early postoperative outcomes, including wound healing, rehabilitation, pain, and fall rates; and reduce the risk of PJIs and revision surgery after TKA. Study Design: Systematic review; Level of evidence, 2. Methods: Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, PubMed, Embase, Scopus, and Web of Science were searched for articles published up to July 2025. The inclusion criteria encompassed studies having a vitamin D–supplemented arm in the TKA context, while case reports, editorials, and other study designs were excluded. A total of 562 studies were found initially. Data on correction of vitamin D deficiency, functional and patient-reported outcomes, complications, revisions, and infections were independently extracted. Methodological quality was assessed using the ROBINS-I (Risk of Bias in Non-Randomized Studies of Interventions) and RoB 2 (Cochrane Risk of Bias Tool) tools. Results: A total of 11 studies met the inclusion criteria. Among the fragmented evidence, vitamin D supplementation was linked to minimal rehabilitation improvements. It was also associated with lower overall complication and PJI rates but was not significantly associated with changes in pain scores. The considerable heterogeneity in study designs, supplementation protocols, and baseline vitamin D status limited the certainty of findings. Conclusion: Our study demonstrated that perioperative vitamin D supplementation may enhance early recovery and lower complication rates after TKA. However, current evidence is inconsistent and insufficient to support universal supplementation. High-quality randomized trials are needed to establish its clinical efficacy and optimal dosing strategies as well as to refine postoperative recovery protocols and infection prevention strategies.
Vosoughi et al. (Fri,) studied this question.