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

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.

One hundred seven patients undergoing primary total knee arthroplasty were randomized to receive 50,000 international units vitamin D₃ (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.

There was no difference in improvement of KSS at 3 weeks (+4.8 points vitamin D₃ versus +3.0 points placebo; P = .6) or 6 weeks (+14.5 points vitamin D₃ versus +12.4 points placebo; P = .5) from baseline. There was no difference in change in TUGT at 3 weeks (+1.2 seconds vitamin D₃ versus +0.6 seconds placebo; P = .6) or 6 weeks (-0.3 seconds vitamin D₃ 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 D₃ cohort (P = 1.0).

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 I, therapeutic study.