Could Vitamin D Help Fight Multiple Sclerosis?
Supplementation appears safe but experts say it's too soon for general recommendation
By Amy Norton
WEDNESDAY, Dec. 30, 2015 (HealthDay News) -- High-dose vitamin D appears safe for people with multiple sclerosis, and it may help quiet the immune system hyperactivity that marks the disease, a small clinical trial finds.
The study, published online Dec. 30 in Neurology, bolsters evidence that vitamin D might benefit people with MS.
But clinical trials are still underway to answer the big question: Does taking vitamin D improve MS symptoms and alter the course of the disease?
The current study shows only that high doses -- 10,400 IU a day -- reduce the proportion of certain immune-system cells that have been implicated in the MS disease process.
"I'm not going to make any claims beyond that," said senior researcher Dr. Peter Calabresi, a professor of neurology at Johns Hopkins University in Baltimore.
"We don't have enough data here to guide clinical practice," he stressed.
Bruce Bebo, executive vice president of research for the National Multiple Sclerosis Society, echoed that caution.
"This study was not designed to look at efficacy against MS. It was too small and too short to do that," said Bebo, whose group helped fund the research.
Still, Bebo added, the findings are important for other reasons. For one, he said, "they give us some hints about the mechanisms that explain the higher MS risk associated with low vitamin D."
MS is caused by an abnormal immune system attack on the protective sheath surrounding nerve fibers in the brain and spine. That leads to symptoms such as muscle weakness, numbness, vision problems, and difficulty with balance and coordination.
Typically, MS symptoms flare up periodically, followed by periods of remission. Over time, the disease can cause worsening problems with walking and mobility.
The precise cause of MS is unknown, but researchers believe it involves a combination of genetic vulnerability and certain environmental triggers. Inadequate vitamin D -- a nutrient needed for normal immune function -- is considered one of the suspects.
That's partly based on studies showing an association between blood levels of vitamin D and the risk of developing MS. But there is also more-direct evidence, Bebo said. For example, research has shown that vitamin D can reduce the effects of an MS-like disease in lab mice.