Objectives: This systematic review investigates the impact of vitamin D supplementation on postoperative outcomes following total knee and hip arthroplasty, considering 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 up to April 2026. Eligible studies were randomized clinical trials evaluating vitamin D supplementation in patients undergoing total knee or hip arthroplasty. Two reviewers independently screened studies, extracted data, and assessed quality using the Cochrane RoB-2. A qualitative synthesis was performed because of substantial methodological heterogeneity.

Results: Five randomized controlled trials involving 519 patients were included. Higher-dose and oral regimens produced greater increases in serum 25(OH)D, including higher postoperative concentrations with 2000 vs 800 IU at 24 months (45.5 vs 37.1 ng/mL) and with oral vs intramuscular 600,000 IU at postoperative day 14. However, most studies found no significant between-group differences in functional measures, pain scores, complications, and clinical outcomes. One study showed 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, but current evidence for consistent benefit on broader postoperative functional and clinical outcomes after joint arthroplasty remains limited and mixed.

Level of Evidence: Level II

Keywords: Vitamin D, total knee arthroplasty, total hip arthroplasty, supplementation