, results from a randomized control trial show. However, at least one expert believes the study’s exclusion criteria may have been too broad.
The investigation of vitamin D to prevent relapse of MS is based on older observational studies of people who already had higher blood levels of vitamin D and were less likely to develop MS, said study investigator Ellen Mowry, MD, Richard T. and Frances W. Johnson professor of neurology, Johns Hopkins University, Baltimore.
Later research where participants were given vitamin D as a therapeutic option for MS “were disappointing as the vitamin D had minimal effect,” she said.
“While we were excited by early data suggesting that vitamin D may have an important impact on MS, it’s essential to follow those linkage studies with the gold standard clinical evidence, which we have here,” Dr. Mowry added.
The findings were published online in eClinicalMedicine.
No difference in relapse risk
The multisite, phase 3 Vitamin D to Ameliorate MS (VIDAMS) clinical trial included 172 participants aged 18-50 years with RRMS from 16 neurology clinics between 2012 and 2019.
Inclusion criteria were having one or more clinical episodes of MS in the past year and at least one brain lesion on MRI in the past year or having two or more clinical episodes in the past year. Eligible participants also had to have a score of 4 or less on the Kurtzke Expanded Disability Status Scale.
A total of 83 participants were randomly assigned to receive low-dose vitamin D3 (600 IU/day) and 89 to receive high-dose vitamin D3 (5,000 IU/day). Each participant took the vitamin tablet with glatiramer acetate, a synthetic protein that simulates myelin.
Participants were assessed every 12 weeks to measure serum 25(OH)D levels and every 24 weeks for a number of movement and coordination tests, as well as two 3T clinical brain MRIs to check for lesions.
By the trial’s end at 96 weeks, the researchers found no differences in relapse risk between the high- and low-dose groups (P = .57). In addition, there were no differences in MRI outcomes between the two groups.
Dr. Mowry said that more than a few people have asked her if she is disappointed by the results of the VIDAMS trial. “I tell them that no, I’m not – that we are scientists and clinicians, and it is our job to understand what they can do to fight their disease. And if the answer is not vitamin D, that’s OK – we have many other ideas.”
These include helping patients minimize cardiometabolic comorbidities, such as heart disease and blood pressure, she said.
Exclusion criteria too broad?
Commenting on the findings, Alberto Ascherio, MD, professor of epidemiology and nutrition at Harvard School of Public Health, Boston, said a key principle of recommending vitamin supplements is that they are, generally speaking, only beneficial for individuals with vitamin deficiencies.
He noted that “patients with vitamin D deficiency (25(OH)D < 15 ng/mL, which corresponds to 37.5 nmol/L) were excluded from this study. Most importantly, the baseline mean 25(OH)D levels were about 30 ng/mL (75 nmol/L), which is considered a sufficient level (the IOM considers 20 ng/mL = 50 nmol/L as an adequate level),” with the level further increasing during the trial due to the supplementation.
“It would be a serious mistake to conclude from this trial (or any of the previous trials) that vitamin D supplementation is not important in MS patients,” Dr. Ascherio said.
He added that many individuals with MS have serum vitamin D levels below 20 ng/mL (50 nmol/L) and that this was the median serum value in studies among individuals with MS in Europe.
“These patients would almost certainly benefit from moderate doses of vitamin D supplements or judicious UV light exposure. Most likely even patients with sufficient but suboptimal 25(OH)D levels (between 20 and 30 ng/mL, or 50 and 75 nmol/L) would benefit from an increase,” he said.
The study was funded by the National Multiple Sclerosis Society, Teva Neuroscience, and the National Institute of Health. Dr. Mowry reported grant support from the National MS Society, Biogen, Genentech, and Teva Neuroscience; honoraria from UpToDate; and consulting fees from BeCare Link.
A version of this article first appeared on Medscape.com.