Vitamin D Injections for Warts Work by Boosting the Antimicrobial Peptide LL-37
Injecting vitamin D directly into warts cleared 40% of them completely and significantly boosted the antimicrobial peptide LL-37, revealing how the treatment activates the skin's natural viral defense.
Quick Facts
What This Study Found
Injecting vitamin D directly into common warts (verruca vulgaris) significantly increased expression of the antimicrobial peptide LL-37 (cathelicidin) in the skin (p=0.003). Of 20 patients treated, 40% showed complete wart clearance and 35% showed partial response. Warts that cleared completely had the highest LL-37 expression (p=0.022).
After treatment, the skin also showed decreased epidermal thickness and reduced inflammatory cell density, indicating the immune response was shifting from chronic inflammation toward effective viral clearance driven by LL-37.
Key Numbers
n=20 patients · 10 healthy controls · 40% complete response · 35% partial response · 25% no response · LL-37 increase p=0.003 · Complete responders p=0.022 · Max 4 sessions every 2 weeks
How They Did This
Twenty patients with multiple common warts received intralesional vitamin D3 injections every 2 weeks for up to 4 sessions or until warts cleared. Skin biopsies were taken before and after treatment and compared to samples from 10 healthy controls. LL-37 expression was assessed by immunohistochemistry. Histopathological changes in the epidermis and dermis were also evaluated.
Why This Research Matters
LL-37 is the body's primary antimicrobial peptide and plays a key role in fighting viral infections in the skin. This study provides a mechanistic explanation for why vitamin D injections work against warts — they boost the skin's natural LL-37 production, helping the immune system recognize and clear the HPV virus. This connects two major research areas: vitamin D's role in immunity and cathelicidin's antiviral properties.
The Bigger Picture
LL-37 is increasingly recognized as a frontline defender in skin immunity, with roles in fighting bacteria, viruses, and fungi. This study adds wart clearance to LL-37's growing resume and demonstrates that its expression can be deliberately upregulated through vitamin D — a finding with implications for other skin infections and conditions where cathelicidin deficiency plays a role.
What This Study Doesn't Tell Us
Small sample size (20 patients) limits generalizability. No placebo or sham injection control group — response could partly be due to the injection itself triggering local immunity. The study was not blinded. No long-term follow-up to assess recurrence rates.
Questions This Raises
- ?Could topical or oral vitamin D supplementation boost LL-37 enough to prevent wart recurrence?
- ?Would patients with low baseline vitamin D levels show even greater responses to intralesional injection?
- ?Could this LL-37-boosting mechanism be exploited for other HPV-driven conditions like genital warts or cervical dysplasia?
Trust & Context
- Key Stat:
- 40% complete wart clearance Vitamin D injections significantly increased LL-37 expression in wart tissue (p=0.003), with the highest LL-37 levels in patients whose warts cleared completely.
- Evidence Grade:
- This is a small interventional study with 20 patients and no control group receiving sham injections. While the immunohistochemical evidence linking vitamin D to LL-37 upregulation is compelling, the lack of blinding and small sample limit the strength of the clinical efficacy findings.
- Study Age:
- Published in 2022. The connection between vitamin D and cathelicidin expression remains an active research area, and intralesional vitamin D for warts continues to be studied.
- Original Title:
- Intralesional injection of vitamin D in verruca vulgaris increases cathelicidin (LL37) expression; therapeutic and immunohistochemical study.
- Published In:
- The Journal of dermatological treatment, 33(1), 291-296 (2022)
- Database ID:
- RPEP-06510
Evidence Hierarchy
Frequently Asked Questions
How does vitamin D help clear warts?
When injected directly into warts, vitamin D boosts production of LL-37, an antimicrobial peptide that helps your immune system fight the HPV virus causing the wart. In this study, patients whose warts cleared completely had the highest LL-37 levels, showing a direct link between the peptide and treatment success.
What is LL-37 and why does it matter for skin infections?
LL-37 (cathelicidin) is your body's main antimicrobial peptide in the skin. It kills bacteria, viruses, and fungi by disrupting their membranes. This study showed that vitamin D can boost LL-37 production in wart tissue, suggesting the peptide plays a key role in helping the immune system recognize and clear HPV-infected skin cells.
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Cite This Study
https://rethinkpeptides.com/research/RPEP-06510APA
Sorour, Neveen E; Elesawy, Fatma M; Abdou, Asmaa G; Abdelazeem, Sara E; Akl, Essam M. (2022). Intralesional injection of vitamin D in verruca vulgaris increases cathelicidin (LL37) expression; therapeutic and immunohistochemical study.. The Journal of dermatological treatment, 33(1), 291-296. https://doi.org/10.1080/09546634.2020.1750554
MLA
Sorour, Neveen E, et al. "Intralesional injection of vitamin D in verruca vulgaris increases cathelicidin (LL37) expression; therapeutic and immunohistochemical study.." The Journal of dermatological treatment, 2022. https://doi.org/10.1080/09546634.2020.1750554
RethinkPeptides
RethinkPeptides Research Database. "Intralesional injection of vitamin D in verruca vulgaris inc..." RPEP-06510. Retrieved from https://rethinkpeptides.com/research/sorour-2022-intralesional-injection-of-vitamin
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Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.