High-dose vitamin D supplementation increased vitamin D levels in the blood, was safe and tolerable, and reduced the proportion of immune cells that are thought to drive disease, in a small study of 40 people with relapsing-remitting MS.

The trial was too small to detect differences in disease activity, but a larger Society sponsored trial of vitamin D supplementation is currently recruiting participants.

The team (Elias S. Sotirchos, MD, Pavan Bhargava, MD, Peter A. Calabresi, MD, and colleagues, Johns Hopkins University School of Medicine, Baltimore) has published results in Neurology (published early online, December 30, 2015). Dr. Bhargava was funded by a Sylvia Lawry Physician Fellowship from the National MS Society.

Multiple sclerosis involves immune attacks on the brain and spinal cord. A number of genetic and environmental factors influence whether a person will develop MS. These factors may also impact the severity of the disease. There is growing scientific evidence that low levels of vitamin D in the blood are a risk factor for developing MS. In lab mice, vitamin D can reduce the effects of EAE, an MS-like disease, and some evidence suggests it may impact ongoing disease activity in people who have MS.An important initial step to pursuing this lead was to determine whether taking large doses of vitamin D was safe and provides any hints of impact against the immune activity that is associated with MS. A team at Johns Hopkins University undertook this preliminary step to determine whether a larger-scale clinical trial was warranted.Investigators randomly assigned 40 people with MS to receive either 800 IU of vitamin D, or 10,400 IU, daily for six months (nutritional supplementation is typically 600 IU). Participants were maintained on standard disease modifying treatment throughout the course of the study. Blood tests were done at three and six months to determine whether the dose increased the levels of vitamin D in the blood, and immune system effects. Blood and urine were assessed for calcium levels, since an excess of calcium can be a side effect of high-dose vitamin D supplementation. The primary goals of this study were to determine safety and effects on immune activity markers.The investigators reported a few adverse events that did not differ between the groups, and they were all minor.Vitamin D levels increased more in the high-dose group, to a level that has been suggested as the optimal target for people with MS. Immune cells known as Th17 cells – which have been suggested to be major players in the immune attack on the brain and spinal cord in MS – were reduced in the high-dose group, but not in the low-dose group. Investigators also found that the higher the levels of vitamin D in the blood, the greater the reduction of Th17 cells.Results were published in Neurology ( published early online, December 30, 2015 ).This team is now conducting a larger trial at several centers nationwide, in which they are recruiting 172 people with relapsing-remitting MS to compare the effectiveness of 600 IU of vitamin D supplementation versus 5000 IU vitamin D supplementation at reducing MS disease activity, when added to standard therapy with glatiramer acetate (Copaxone, Teva Pharmaceutical Industries). The study is funded by a research grant from the National MS Society, with support from the Society’s Greater Delaware Valley Chapter.Further research in the laboratory also is suggesting that vitamin D’s capabilities go beyond immune regulation. Read more Read more about the larger, ongoing study Read more about research on vitamin D and MSCopaxoneis a registered trademark of Teva Pharmaceuticals Industries Ltd.