40 patients with vitamin D deficiency and scheduled for lumbar spinal stenosis surgery were randomized to receive vitamin D supplementation (100,000 IU intramuscular injections of Vitamin D3) or no supplementation. Outcomes of interest included the Oswestry Disability index (ODI), Rolland-Morris Disability Questionnaire (RMDQ), and the Short Form 36 (SF-36) quality of life test. Follow up was performed up to 12 months post-operation. At 6 and 12 months, significantly favourable ODI, SF-36 Mental and SF-36 Physical scores were observed in the supplementation group compared to the control group. No significant differences between groups were observed in RMDQ scores at any time point.