Half an hour of sun exposure daily may lower risk for pediatric IBD

(HealthDay)—Higher sun exposure in the previous summer or winter is associated with a lower risk for having pediatric inflammatory bowel disease (IBD), according to a study recently published in the Journal of Pediatric Gastroenterology and Nutrition.

Elizabeth Ann Holmes, from the Australian National University in Canberra, and colleagues recruited 99 children (ages 0 to 17 years) with IBD from two large hospitals in Melbourne, Australia, as well as 396 control participants from the day surgery unit of one of the hospitals. Surveys assessed demographics, previous sun exposure, the likelihood of sunburn (skin sensitivity) or tanning following sun exposure, use of sun protection, physical activity, and parental smoking and education.

The researchers found that for each 10-minute increment in leisure-time sun exposure in summer or winter, there was a linear 6 percent reduction in the odds of having IBD. Results were consistent when including only the most recently diagnosed cases, only Caucasian cases and controls, and only those with symptom onset within the year prior to study entry and when adjusting for age or physical activity.

"We were unable to explore the mechanism of this effect, and the possibility that it may be mediated by vitamin D," write the authors. "These findings add to growing evidence that higher sun exposure (or vitamin D) is associated with reduced risk of some autoimmune diseases; if replicated, this may provide an avenue toward prevention or reduction in incidence."