Vitamin D and HPV
Most HPV infections clear spontaneously; persistent high-risk HPV drives cervical intraepithelial neoplasia (CIN) and cervical cancer. Vitamin D's immune-modulating role has attracted attention as a possible modifier of HPV clearance. Evidence is preliminary and does not replace vaccination or screening.
Observational data
Multiple cohort studies (Ozgu 2016, Schulte-Uebbing 2014) find lower mean 25(OH)D in women with persistent HPV or CIN than in those clearing infection or with normal cytology. Effect sizes are modest and not consistent across all studies.
Mechanistic plausibility
Vitamin D receptors expressed in cervical epithelium. Calcitriol modulates cell-cycle proteins and can inhibit HPV E6/E7-driven proliferation in vitro. Vitamin D-dependent innate immunity may help clear early HPV infection. These are plausible mechanisms; clinical translation is unproven.
Supplementation trials
Very small pilot trials of vitamin D supplementation in low-grade CIN have reported histological regression rates comparable to expected natural history. No large trial has established supplementation as a CIN treatment. Standard management (colposcopy, observation for low-grade lesions, LEEP for high-grade) remains the evidence-based approach.
What actually prevents HPV-related cancer
- HPV vaccination — 9-valent (Gardasil 9) prevents ~90% of cervical cancers. Best given at ages 9-14 before sexual debut but effective up to age 45.
- Cervical screening — HPV testing ± cytology per age and country guidelines.
- Appropriate treatment of high-grade CIN.
- Smoking cessation — smoking is an independent HPV-persistence and cervical cancer risk factor.
- Vitamin D correction is a reasonable adjunct in deficient women; not a substitute for the above.