Association of prediagnostic serum vitamin D levels with the development of basal cell carcinoma.

We investigated the association between serum 25-hydroxyvitamin D (25(OH)D) levels and basal cell carcinoma (BCC) risk in a nested case-control study at Kaiser Permanente Northern California (KPNC). A total of 220 case patients with BCC diagnosed after serum collection were matched to 220 control subjects. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using conditional logistic regression.