Malignant Melanoma: Vitamin D Status as a Risk and Prognostic Factor - Meta-analyses and Systematic Review.
Level 3 - non-randomized controlled study
Systematic review and meta-analyses of observational (case-control and cohort) studies.
PubMed 39740829 · doi:10.21873/anticanres.17390
What was done
A systematic review and nine meta-analyses of studies retrieved from Medline (via PubMed) and ISI (Web of Science) were conducted to assess the relationship between 25(OH)D vitamin D status, cutaneous malignant melanoma risk, and melanoma prognostic indicators (Breslow thickness, mitotic rate, tumor stage, and ulceration status).
What was found
The abstract reports no numerical effect sizes, sample counts, or confidence intervals. It states that patients with melanoma had significantly lower mean 25(OH)D levels than healthy controls. There was a non-significant trend toward increased melanoma risk with vitamin D deficiency (<=20 vs. >20 ng/ml), which became statistically significant in subgroup analyses of Southern European studies. Low serum levels were significantly associated with greater Breslow thickness, presence of mitoses, and ulcerated primary tumors (but not higher tumor stage), whereas vitamin D deficiency was significantly associated with thicker tumors, mitotic tumors, and higher tumor stages.
Why it matters
This review links vitamin D deficiency with both melanoma susceptibility and adverse histopathological tumor features. It adds observational synthesis to the debate surrounding the tumor-protective role of vitamin D in skin cancer.
Limits
The abstract provides no quantitative data, odds ratios, participant numbers, or study counts. Because it synthesizes observational studies, it cannot establish causality or exclude confounding factors such as reverse causation, post-diagnosis lifestyle changes, or systemic inflammation.