A new study, conducted in mice by researchers at Johns Hopkins University School of Medicine and partially funded by the National Institutes of Health, has reportedly revealed that vitamin D may benefit people with multiple sclerosis (MS), an autoimmune disorder apparently caused when the immune system wrongly attacks a person’s own cells. Although the study results, published in Proceedings of the National Academy of Sciences, have not been confirmed in humans with the disease, scientists note that they may help better explain how the disease works, how to treat it and why certain people are more prone to developing it. 

Because the disease is more prevalent in regions of the world farthest from the equator where there is less sunshine—the main natural source of vitamin D, researchers have long-suspected a link between the disease and sun exposure. “With this research, we learned vitamin D might be working not by altering the function of damaging immune cells but by preventing their journey into the brain,” said lead researcher Anne Gocke. “If we are right, and we can exploit Mother Nature’s natural protective mechanism, an approach like this could be as effective as and safer than existing drugs that treat MS.”
 
For the study, Gocke and her colleagues simultaneously gave mice the rodent form of MS and a high dose of vitamin D, observing that this protected the mice from showing disease symptoms. The study team remarked that with the clinical trial on vitamin D supplementation ongoing, no one is certain whether it will actually work to prevent or slow the progression of MS in humans. “But this new research,” study co-author Peter Calabresi said, “can offer the opportunity to study samples taken from participants to see whether vitamin D is having the same effect on human cells as it appears to be having in mice.” See Johns Hopkins School of Medicine News Release, December 5, 2013.