A University of Wisconsin study suggests that UV exposure, totally independent of vitamin D production, suppresses an animal model of multiple sclerosis — another indication that UV exposure’s positive influence extends well beyond vitamin D production.

Researchers, including University of Wisconsin vitamin D pioneer Dr. Hector DeLuca, used UVB light on subjects with experimental autoimmune encephalomyelitis, a form of multiple sclerosis studied in animal models. The subjects were less likely to develop MS, despite the fact that their vitamin D levels did not change significantly. MS rates are significantly higher in sun-deprived parts of the world — another reason researchers speculate that MS is inhibited by sun exposure.

Vitamin D pioneer Dr. Michael Holick has pointed out that UV exposure triggers the production of much more than just vitamin D in the skin, and that research has yet to identify the function of many of these metabolites. His point: They must be responsible for something, so it isn’t right to simply dismiss UV exposure.

“These results suggest that UVR is likely suppressing disease independent of vitamin D production,” the Wisconsin team wrote. “Vitamin D supplementation alone may not replace the ability of sunlight to reduce MS susceptibility.”