Researchers from Johns Hopkins University reported that a high dose of vitamin D3 is safe for people with multiple sclerosis (MS) and may help regulate the body’s hyperactive immune response. Findings from the study are published in Neurology

Earlier research has shown that low vitamin D levels are associated with an increased risk of developing MS. In the new study, 40 patients with relapsing-remitting MS were given either 10,400 IU or 800 IU of vitamin D3 supplements daily for 6 months. Currently, the daily recommended dose of vitamin D3 is 600 IU. For patients with MS, a suggested range of 40-60ng/mL of vitamin D has been proposed..

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Blood tests performed at study initiation and at Months 3 and 6 measured vitamin D levels and the response in the immune system’s T cells. The study found that patients taking the high dose supplementation reached target vitamin D levels whereas patients taking the low dose did not.  Also, patients taking the high dose had a reduction in the percentage of T cells related to MS severity–specifically IL-17+CD4+ and CD161+CD4+ cells.For patients with baseline levels >18ng/mL, every additional 5ng/mL increase in vitamin D led to a 1% decrease in the percentage of IL-17+CD4+ T cells in the blood. The authors noted patients taking the low dose supplementation did not have any significant changes in the percentages of their T cell subsets. 

Other studies are in the works to determine if the changes in inflammatory T cell responses “translate to a reduced severity of disease,” stated Peter Calabresi, MD. “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.” 

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