Purpose: This evidence-based practice quality improvement project aimed to holistically address chronic pain—impacting over 100 million Americans—by exploring the potential of vitamin D supplementation as a non-opioid, integrative treatment. Theoretical Framework: Guided by the Johns Hopkins Nursing Evidence-Based Practice Model (JHEBP), the project aligns with holistic nursing by emphasizing whole person and evidence-informed, non-pharmacologic interventions. Method: The project was implemented at a free clinic in Central Appalachia, involving 30 vitamin D-naïve patients with chronic pain who received a weekly oral dose of 50,000 IUs of vitamin D for 12 weeks. Participants completed pre- and post-surveys, clinical evaluations, and serum level testing to assess outcomes. Findings: After 12 weeks, patients showed statistically significant reductions in pain intensity (p = 0.007) and pain interference (p = 0.020), with serum vitamin D levels rising from 24 to 36 ng/mL (p < 0.001) and a large effect size (Cohen's d = 1.28); 91% reported subjective benefit. Implications: This project supports incorporating vitamin D as part of a holistic, equitable, and evidence-based approach to chronic pain management, reducing reliance on opioids and advancing integrative nursing practice.