Fig. 2From: The efficacy of oral vitamin D supplements on fusion outcome in patients receiving elective lumbar spinal fusion—a randomized control trialKaplan–Meier analysis showed a significantly shorter time to fusion in the experimental group than in the control group (169 days vs. 185 days [interquartile range: 88–182 days vs. 176–324 days], P = 0.028)Back to article page