Patients with multiple sclerosis (MS) who took about 17 times the recommended daily allowance of vitamin D3 (cholecalciferol) showed multiple immunomodulatory improvements, according to a study published online December 30, 2015 in Neurology.
“These results are exciting, as vitamin D has the potential to be an inexpensive, safe, and convenient treatment for people with MS,” said study author Peter A. Calabresi, MD, Professor of Neurology and Director of the Multiple Sclerosis Center at Johns Hopkins University School of Medicine, in Baltimore, MD.
Low serum levels of vitamin D are known to be associated with an increased risk for MS. Previous research has shown that supplemental vitamin D ameliorated experimental MS in mice—but few studies in humans have been performed.
In this double-blind pilot study, Dr. Calabresi and colleagues compared the effects of high-dose (10,400 IU) vs standard dose (800 IU) vitamin D3 in 40 patients with relapsing-remitting MS. (The recommended daily allowance of vitamin D3 is 600 IU.)
In patients in the high-dose group, blood tests at 6 months revealed a reduction in the proportion of interleukin-17 T cells, which are implicated as a major contributor to the immunopathogenesis of MS. Every 5 ng/ml increase in vitamin D led to a 1% decrease in the percentage of interleukin-17 T cells in the blood of high-dose patients (when the increase in vitamin D in the blood was greater than 18 ng/ml), researchers found.
Patients in the low-dose group, though, didn’t show any changes in T cells.
Side effects from the vitamin supplements were minor and about the same between the two groups. One person in each group had a relapse of disease activity.
It’s too soon to tell from this study whether high-dose vitamin D3 slows the progression or halts the symptoms of MS, Dr. Calabresi said. “More research is needed to confirm these findings with larger groups of people and to help us understand the mechanisms for these effects, but the results are promising,” he said.
To that end, study co-author Ellen Mowry, MD, Associate Professor of Neurology at Johns Hopkins, has now begun a multi-center placebo-controlled clinical trial to investigate whether high-dose vitamin D3 can reduce relapses and slow disease progression in MS patients.