Methods/Design: We will conduct a randomized, placebo-controlled, double-blind clinical trial. Our study
population will include 380 cases with one-level and unilateral lumbar disc herniation with duration of discogenic
pain less than 8 weeks. Individuals who do not have any contraindications, will be divided into three groups
based on serum 25-hydroxy vitamin D3 level, and each group will be randomized to receive either a single-dose
300,000-IU intramuscular injection of vitamin D3 or placebo. All patients will be under conservative treatment.
Pre-treatment and post-treatment assessments will be performed with the McGill Pain Questionnaire and a visual
analogue scale. For the 15-day duration of this study, questionnaires will be filled out during telephone interviews
every 3 days (a total of five times). The initial and final interviews will be scheduled at our clinic. After 15 days,
serum 25-hydroxy vitamin D3 levels will be measured for those who have received vitamin D3 (190 individuals).