(A) Association between smoking intensity and urinary vitamin E metabolite α-CEHC in current smokers. (B) Association between smoking intensity and urinary vitamin E metabolite α-TLHQ in current smokers. (C) Association between smoking intensity and urinary vitamin E metabolite α-TLHQ relative to α-CEHC in current smokers. (D) Association between smoking intensity and urinary vitamin E metabolite α-TOH in current smokers. Results are derived from linear regression model adjusted for age, sex, BMI and alcohol with 95% confidence interval (CI) and presented as percentage difference compared with the reference group. Of the current smokers, the 50% with the lowest pack years is considered the low pack years group, whereas the highest 50% is in the high pack years group. CEHC, carboxymethyl-hydroxychroman.