Purpose

A cohort study was carried out to test the hypothesis that higher vitamin D levels reduce the risk of relapse from melanoma.

Methods

A pilot retrospective study of 271 patients with melanoma suggested that vitamin D may protect against recurrence of melanoma. We tested these findings in a survival analysis in a cohort of 872 patients recruited to the Leeds Melanoma Cohort (median follow-up, 4.7 years).

Results

In the retrospective study, self-reports of taking vitamin D supplements were nonsignificantly correlated with a reduced risk of melanoma relapse (odds ratio= 0.6; 95% CI, 0.4 to 1.1; P=. 09). Nonrelapsers had higher mean 25-hydroxyvitamin D 3 levels than relapsers (49 v 46 nmol/L; P=. 3; not statistically significant). In the cohort (prospective) study, higher 25-hydroxyvitamin D 3 levels were associated with lower Breslow thickness at diagnosis (P=. 002) and were independently protective of relapse and death: the hazard ratio for relapse-free survival (RFS) was 0.79 (95% CI, 0.64 to 0.96; P=. 01) for a 20 nmol/L increase in serum level. There was evidence of interaction between the vitamin D receptor (VDR) BsmI genotype and serum 25-hydroxyvitamin D 3 levels on RFS.

Conclusion

Results from the retrospective study were consistent with a role for vitamin D in melanoma outcome. The cohort study tests this hypothesis, providing evidence that higher 25-hydroxyvitamin D 3 levels, at diagnosis, are associated with both thinner tumors and better survival from melanoma, independent of Breslow thickness. Patients with melanoma, and those at high risk of melanoma, should seek to ensure vitamin D sufficiency. Additional studies are needed to establish optimal serum levels for patients with melanoma.