Vitamin D insufficiency and serum levels related to the incidence and stage of cutaneous melanoma: a systematic review and meta-analysis.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of cohort and case-control studies
PubMed 37199748 · doi:10.1097/CMR.0000000000000897
What was done
A systematic review and meta-analysis of five databases up to July 11, 2022, included 14 cohort and case-control studies. The analysis evaluated the relationship between 25-hydroxy vitamin D levels or vitamin D insufficiency and cutaneous melanoma (CM) incidence compared to healthy controls, as well as associations with Breslow tumor depth and metastatic disease.
What was found
Vitamin D level <20 ng/dl was significantly associated with higher CM incidence (pooled RR 1.45, 95% CI 1.04-2.02). Lower mean vitamin D was associated with Breslow depth >1 mm (SMD 0.19, 95% CI 0.11-0.28), and vitamin D >20 ng/dl was associated with Breslow depth <1 mm (pooled RR 0.69, 95% CI 0.58-0.82). No statistically significant associations were found between mean vitamin D level and CM incidence (pooled SMD -0.39, 95% CI -0.80 to 0.01) or between vitamin D levels and metastasis (pooled SMD -0.13, 95% CI -0.38 to 0.12).
Why it matters
This study quantitatively synthesizes observational evidence linking lower vitamin D levels with higher melanoma risk and deeper primary tumor invasion, highlighting vitamin D insufficiency as a potential correlate of melanoma presentation.
Limits
The included studies were observational (cohort and case-control), precluding causal inference. Total participant count was not stated in the abstract, and potential residual confounders (such as UV radiation exposure, sun protection behavior, and timing of blood sampling) were not described.