Study Finds High-Dose Vitamin D Not Effective in Reducing Risk of Relapse in MS

Research findings debunk notion that vitamin D supplementation reduces multiple scleorsis relapses.

Vitamin D is a hormone and nutrient that can be obtained from diet or supplements and is manufactured in the skin when it is exposed to sunlight. It provides several functions, including contributing to bone health and supporting the cardiovascular system, brain and muscles. Many people with multiple sclerosis (MS) are not able to make vitamin D from sunlight, and low vitamin D levels are associated with an increased risk of MS relapse.

The Vitamin D to Ameliorate MS (VIDAMS) trial, sponsored by the National Multiple Sclerosis Society, is a phase 3, double-blind, randomized, controlled trial that compared high doses to low doses of vitamin D added to Copaxone (glatiramer acetate) and the effect they had on lowering the risk of relapse in adults with established relapsing-remitting MS (RRMS). The study results were published in the May 2023 issue of eClinicalMedicine.

The trial, led by Sandra D. Cassard, D.Sc., from the Department of Neurology at Johns Hopkins University School of Medicine, enrolled 172 patients with RRMS diagnosed less than 10 years before enrollment. The group was randomized to receive either high-dose vitamin D (5,000 international units daily) or low-dose vitamin D (600 units daily). All began receiving Copaxone 20 mg daily injections 30 days before starting vitamin D supplementation. The mean age in both groups was about 34 years.

The primary objective was to determine whether high-dose vitamin D compared with low-dose vitamin D lowered the risk of relapse at 96 weeks. Secondary endpoints included differences in new or enlarging lesions, brain volume loss and disease severity.

At 96 weeks, no differences were seen between the two groups in relapse rates (34% in the high-dose group versus 32% in the low-dose group). Secondary outcomes were also not met. The researchers concluded that high-dose vitamin D supplantation does not reduce the risk of relapse in patients with RRMS.

“Although common practice, based on these findings, prescribing [high-dose vitamin D] for the purpose of reducing clinical and imaging disease activity in established RRMS does not appear to be helpful,” wrote Cassard and her colleagues.