Spending more time in the sun in the summer is associated with reduced odds of developing pediatric MS, according to a study published in Neurology. Nicolas Cherbuin, Ph.D., and colleagues recruited children with MS and controls from multiple centers in the United States to examine the correlation of time spent outdoors daily in summer, use of sun protection, and ambient ultraviolet radiation (UVR) dose in the year prior to birth and the year before diagnosis with the risk for pediatric-onset MS. Data were included for 332 children with MS and 534 controls matched for age and sex. Compared with spending less than 30 minutes outdoors daily during the most recent summer, more time spent outdoors was associated with a marked decrease in the odds of developing MS in a fully adjusted model, with evidence of a dose-response (aORs, 0.48 for 30 minutes-1 hour, 0.19 for 1-2 hours). Higher summer ambient UVR dose was also associated with reduced odds of developing MS (aOR, 0.76 per kJ/ m2). “Clarifying the causal effect of modifiable risk factors, such as sun exposure and vitamin D status, could reduce the disease burden associated with MS,” the authors wrote. “Our findings suggest that advising regular time in the sun of at least 30 minutes daily during summer and using sun protection as needed… maybe a worthwhile intervention to reduce the incidence of pediatric MS.”