The Impact of Vitamin D Supplementation on Postoperative Outcomes Following Total Joint Arthroplasty: A Systematic Review.

OBJECTIVES: This systematic review examines the effects of vitamin D supplementation on postoperative outcomes following total knee and hip arthroplasty, taking into account its role in musculoskeletal health and the high prevalence of vitamin D deficiency among arthroplasty patients. METHODS: A comprehensive search of PubMed, Scopus, Embase, and Web of Science was conducted through April 2026. Eligible studies included randomized clinical trials assessing vitamin D supplementation in patients undergoing total knee or hip arthroplasty. Two reviewers independently screened studies, extracted data, and evaluated methodological quality using the Cochrane RoB-2 tool. Due to substantial methodological heterogeneity, a qualitative synthesis was performed. RESULTS: Five randomized controlled trials comprising 519 patients were included. Higher-dose and oral regimens resulted in greater increases in serum 25(OH)D levels, including higher postoperative concentrations with 2000 IU versus 800 IU at 24 months (45.5 vs. 37.1 ng/mL) and with oral versus intramuscular administration of 600,000 IU on postoperative day 14. However, most studies reported no significant between-group differences in functional outcomes, pain scores, complications, or other clinical endpoints. One study demonstrated significantly greater muscle strength in the supplementation group, including hip abductor strength (P = 0.03) and knee extensor strength (P = 0.01). CONCLUSION: Vitamin D supplementation appears to improve perioperative vitamin D status, particularly with higher-dose and oral regimens. However, current evidence for consistent benefits on broader postoperative functional and clinical outcomes after joint arthroplasty remains limited and inconclusive. LEVEL OF EVIDENCE: II.