Sunlight: Friend or foe? A natural source of vitamin D or a Risk Factor for Cutaneous Malignancy?

Objective: We assessed the relationship between serum 25 hydroxyvitamin D (OH) D levels and the presence of malignancy in patients who underwent surgery for cutaneous skin lesions. Materials and Methods: Three-hundred and ninety-eight patients operated on for cutaneous lesions, had serum 25 (OH) D levels on file, had no known parathyroid pathology, did not concomitantly take bisphosphonate or Vitamin D supplement, and had accessible pathology results were reviewed upon their consent for the retrospective analysis of their data. Demographic characteristics, diagnosis dates, lesion localizations, pathology results, and serum 25 (OH) D levels were noted. Optimal cutoff value for Vitamin D levels was calculated with receiver operating characteristic (ROC) curve analysis and pathology results of the excised lesions and patient characteristics were analyzed according to this value. Results: ROC analysis showed 90% sensitivity and 64% specificity for vitamin D levels of 18.64 ng/ml (area under the curve [AUC] = 0.905; 95% confidence interval 0.87-0.93, P < 0.001). Review of lesions for pathological characteristics showed 207 (52%) benign and 191 (48%) malignant. While no significant relationship was observed between gender and vitamin D levels, a significant difference was identified between advanced age and low Vitamin D levels and the presence of malignancy (P < 0.001). The one-way analysis of variance and Bonferroni's post hoc analysis revealed higher incidences of malignant lesions in the group with low serum 25 (OH) D levels (P < 0.001), in patients aged 65+ years (P < 0.001), in cases localized to the head and neck (P = 0.026), and in males (P = 0.047). Conclusion: We identified a statistically significant relationship between low serum 25 (OH) D levels and the development of cutaneous malignancy.