Estimates are from logistic regression conditioned on the matching variables and
adjusted for exact age, marital status, education, smoking, height and body mass
index. Ptrend was calculated by replacing the fifths of vitamin
D with a continuous variable that was scored as 0, 0.25, 0.5, 0.75 and 1 in the
conditional logistic regression model. Abbreviations: 80%le= 80 percentile; CI =
confidence interval; Ptr = Ptrend.