Association of Vitamin D Levels With Outcome in Patients With Melanoma After Adjustment For C-Reactive Protein

PurposeTo evaluate for an association between 25-hydroxyvitamin D levels (vitamin D) and outcome measures in patients with melanoma after evaluation is controlled for systemic inflammatory response (SIR) on the basis of simultaneous C-reactive protein (CRP) measurement.Materials and MethodsPlasma samples from 1,042 prospectively observed patients with melanoma were assayed for vitamin D and CRP. The associations of demographics and CRP with vitamin D were determined, followed by a determination of the association between vitamin D and stage and outcome measures from the date of blood draw. The vitamin D level was considered sufficient if it was 30 to 100 ng/mL. Kaplan-Meier and Cox regression analyses were performed.ResultsThe median vitamin D level was 25.0 ng/mL. The median follow-up time was 7.1 years. A lower vitamin D was associated with the blood draw during fall/winter months (P < .001), older age (P = .001), increased CRP (P < .001), increased tumor thickness (P < .001), ulcerated tumor (P = .0105...