Vitamin D has small but significant benefits for MS patients: Study
High-dose supplementation eases symptoms, reduces relapses
High doses of vitamin D provide clinically modest but statistically significant benefits for adults with multiple sclerosis (MS), according to a meta-analysis of published clinical trials.
The study found patients who took the supplement saw reductions in disability scores, relapses, and new lesion formation. Those who took vitamin D for more than one year had fewer relapses, the researchers said.
The study, “Role of vitamin D as adjuvant therapy on multiple sclerosis: an updated systematic review and meta-analysis of randomized controlled trials,” was published in the European Journal of Medical Research.
“While signs of potential benefit exist, the evidence remains mixed, highlighting the need for future research,” the researchers wrote.
Studies have linked vitamin D deficiency to an increased risk of MS, an inflammatory disease characterized by damage to certain parts of the brain and spinal cord. However, there’s conflicting evidence that taking a vitamin D supplement, either alone or as an add-on to standard MS therapies, can ease MS symptoms, reduce relapse rates, or slow disease progression.
A look at the evidence
Faced with contradictory evidence, researchers in Egypt conducted a meta-analysis — a pooled assessment of published studies — of previous clinical trials that evaluated the impact of vitamin D supplementation as an add-on therapy in MS.
From a database search, researchers selected 21 randomized controlled trials, in which a total of 1,903 adult patients with any MS subtype were randomly assigned to vitamin D or a placebo. The team compared those who took a high dose of vitamin D to a control group receiving a placebo or a low dose of vitamin D, regardless of the vitamin D form.
Ten studies reported outcomes based on the Expanded Disability Status Scale (EDSS), an established method for assessing disability in MS. The pooled analysis of these studies showed a significant decrease in EDSS scores, indicating less disability, favoring the high-dose vitamin D group over the control group.
“It is essential to highlight that even though the reduction in EDSS was statistically significant, it may not be clinically relevant, as the observed decrease was only 0.17 points,” which “falls well below the 0.5- to 1.0-point change usually considered a clinically meaningful slowing of disability in MS,” the team noted.
Across nine studies, there was no significant difference between the vitamin D supplementation and controls in the annual relapse rate, or the mean number of relapses per patient per year.
But when researchers assessed whether a patient experienced any relapse during the study period (either yes or no), there was a significant decrease in relapses in the vitamin D group compared with controls. Even so, the reduction in relapses appeared to favor only those who took vitamin D for more than one year.
“This temporal threshold likely accounts for why earlier studies with shorter follow-ups failed to observe a protective effect,” the researchers wrote. “Vitamin D’s immunomodulatory actions may require prolonged exposure to manifest clinical benefits.”
In the five studies that reported MRI findings, patients in the vitamin D group had significantly fewer new lesions than the control group.
Vitamin D supplementation, however, did not show benefits in the timed 25-foot walk, or the time it takes to walk 25 feet, or in measures of fatigue or quality of life.
Data from six studies confirmed that those who took vitamin D had significantly higher levels of 25-hydroxy vitamin D, the most abundant form of vitamin D in the bloodstream. Still, “this increase in [25-hydroxy vitamin D] levels might not directly indicate a correction in the clinical condition of the patients,” the researchers wrote.
“Vitamin D supplementation produces statistically significant — yet clinically modest — reductions in disability progression, relapses, and new [lesion] formation without demonstrable effects on fatigue or quality of life,” the team concluded.
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