Odds ratios of BCC by quartile of plasma vitamin D concentrations in NHS and NHS II (stratified by UVB flux).

aAdjusted for age at blood draw, season of blood draw, lab batch, cohort.bAdjusted for age at blood draw, season of blood draw, lab batch, cohort, hair color, burning tendency, numbers of sunburns.cP for interaction between UVB flux and 25-hydroxyvitamin D is 0.07 after adjusted for age at blood draw, season of blood draw, lab batch, cohort.