Vitamin D₃ Supplementation Prior to Total Knee Arthroplasty: A Randomized Controlled Trial

Background: The purpose of this randomized controlled trial was to determine if a one-time dose of vitamin D3 prior to total knee arthroplasty improves function and patient-reported outcomes, while decreasing complications. Methods: One hundred seven patients undergoing primary total knee arthroplasty were randomized to receive 50,000 international units vitamin D-3 (57 patients) or placebo (50 patients) on the morning of surgery. Power analysis determined 45 patients were required in each cohort to detect a minimal clinically important difference of 6 points in the functional component of the 2011 version of the Knee Society Score (KSS), assuming an alpha of 0.05 and power of 80%. KSS and a Timed Up and Go Test (TUGT) were measured preoperatively and at 3 and 6 weeks postoperatively. Results: There was no difference in improvement of KSS at 3 weeks (+4.8 points vitamin D-3 versus +3.0 points placebo; P = .6) or 6 weeks (+14.5 points vitamin D-3 versus +12.4 points placebo; P = .5) from baseline. There was no difference in change in TUGT at 3 weeks (+1.2 seconds vitamin D-3 versus +0.6 seconds placebo; P = .6) or 6 weeks (-0.3 seconds vitamin D-3 versus -0.9 seconds placebo; P = .6) from baseline. There were 4 complications in the placebo cohort within the first 90 days postoperatively and 5 complications in the vitamin D-3 cohort (P = 1.0). Conclusion: Supplementation with 50,000 international units vitamin D3 on the day of surgery failed to demonstrate statistical significant differences in functional KSS, TUGT times, or complications in the early postoperative period compared to placebo. Level of Evidence: Level I, therapeutic study. (c) 2022 Elsevier Inc. All rights reserved.