Adjusted odds ratios of melanoma by categories of serum 25(OH)D levels.

OR, odds ratio; CI, confidence interval. Conditional logistic regression models adjust for age at randomization, date of blood draw, height, weight, dietary cholesterol, and skin behavior (e.g., skin burns easily in prolonged direct sunlight (no/yes/missing)). Darker months = November–April; lighter months = May–October. *P-values based on test for trend.