Vitamin D-Binding Protein Genotype, Ultraviolet radiation exposure, 25-Hydroxyvitamin D and MS. Depicted are the odds ratios (ORs) and 95% confidence intervals (CIs) of the independent associations of serum 25-hydroxyvitamin D levels (Panel A) or cumulative lifetime ultraviolet radiation exposure (Panel A) with risk of multiple sclerosis/clinically isolated syndrome stratified by dominant genotype of SNP rs7041 within each racial/ethnic group. Serum 25-hydroxyvitamin D levels were log transformed and adjusted for BMI and season. Odds ratios are adjusted by age, sex, smoking, genetic ancestry, HLA-DRB1*15:01 (rs3135388) 25-hydroxyvitamin D (Panel A) or lifetime ultraviolet radiation exposure (Panel B). In blacks, AA is the most common genotype (n = 173, 70.0%; AC/CC n = 74, 30.0%). Among Hispanics, the distribution is AA n = 87, 22.9% and AC/CC n = 293, 77.1%; in whites, AA n = 108, 21.0% and AC/CC n = 406, 79.0%.