The association between serum vitamin D level and risk and prognosis of melanoma: a systematic review and meta-analysis.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational studies
PubMed 31919907 · doi:10.1111/jdv.16189
What was done
A systematic review and meta-analysis of online databases through October 31, 2018, evaluated the association between serum vitamin D levels and melanoma risk and prognosis. The review pooled data from 25 studies involving 11,166 patients with melanoma.
What was found
Mean serum vitamin D levels did not differ significantly between melanoma patients and controls (standardized mean difference [SMD] -0.185, 95% CI -0.533 to 0.162). However, vitamin D deficiency was significantly more prevalent in melanoma patients than in controls (odds ratio 2.115, 95% CI 1.151 to 3.885). Serum vitamin D levels were significantly higher in patients with lower Breslow thickness (<=1 mm vs. >1 mm: SMD 0.243, 95% CI 0.160 to 0.327), and patients with lower vitamin D levels had significantly higher mortality (hazard ratio 1.558, 95% CI 1.258 to 1.931).
Why it matters
The findings link lower vitamin D status to thicker primary tumors and increased mortality in melanoma, supporting its role as a potential prognostic marker or target for prospective clinical trials.
Limits
The review relies on observational studies, which cannot establish causality and remain susceptible to confounding factors like sun avoidance behavior, phototype, or reverse causation. Cutoffs defining vitamin D deficiency, timing of blood draws, and degree of adjustment for confounders are not detailed in the abstract.
Cited by
- supports Skin cancer patients have relatively low levels of vitamin D rather than elevated levels.