New research published in JAMA Neurology suggests higher vitamin D levels in early stage multiple sclerosis may slow disease onset and progression.
Multiple sclerosis (MS) is a well-covered disease on this blog and website, due to the heavy volume of research published to date on the link between vitamin D and MS. Studies have consistently shown a link between low vitamin D intake/levels and increased risk of getting MS. Studies have further found a link between lack of sun exposure and increased risk of getting MS.
There is also a link between vitamin D levels and disease progression, with observational studies showing that lower vitamin D levels are associated with faster progressing MS. Some small experimental trials have also shown that supplementation may slow disease progression or onset.
In the present study, researchers honed in on the role of vitamin D levels on the progression of MS by looking at patients with early stage MS (clinically isolate syndrome, or CIS) who enrolled into a randomized controlled trial looking at the intervention interferon beta-1b. The advantage of this approach is that all patients started the study with a similar disease stage and were placed on similar interventions.
The researchers looked at 468 patients enrolled in the BENEFIT study, a randomized controlled trial that administered the drug interferon beta-1b (IFNB-1b, marketed under trade names Betaferon and Betaseron) or placebo to patients with early symptoms of MS. All patients took IFNB-1b or placebo until they were diagnosed with definite MS (sometimes early stage MS does not convert to definite MS). If they were diagnosed with definite MS, the patients had the choice to begin taking open-label IFNB-1b for five years, whether or not they took the drug or placebo during the trial.
During the study, the researchers measured vitamin D levels [25(OH)D] at baseline, 6, 12 and 24 months. Did vitamin D influence the progression or onset of MS? Here’s what they found:
- At baseline, patients with higher vitamin D levels had lower number of T2 lesions and higher brain volume.
- During the 5 years of follow-up, 377 patients (81.3%) converted to definite MS by clinical and MRI criteria. The risk of conversion to definite MS decreased by 50% for every 20 ng/ml rise in vitamin D levels.
- For every 20 ng/ml increase in vitamin D levels at baseline, 6 months and 12 months, there was a 57% lower lesion rate between 12 and 60 months follow-up and a 63% lower rate between 24 and 60 months follow-up. The implication here is that the longer the follow-up, the bigger the impact of vitamin D levels.
- For every 20 ng/ml increase in vitamin D levels at baseline, 6 months and 12 months, there was a non-significant 27% decrease in risk of relapse over the 5 year follow-up.
- For every 20 ng/ml increase in vitamin D levels at baseline, 6 months and 12 months, there was a 20% decrease per year in T2 lesion volume over the 5 year follow-up.
The researchers concluded:
“In summary, in this large longitudinal study among patients with CIS randomized to early vs late treatment with IFNB-1b, we found that higher serum 25(OH)D levels robustly predicted a lower degree of MS activity, MRI lesion load, brain atrophy, and clinical progression during the 5 years of follow-up.”
Furthermore, the researchers mused over their study’s clinical application:
“Although controlled studies currently underway may provide more definitive answers as to the therapeutic value of further increasing already adequate vitamin D levels, our results suggest that identification and correction of vitamin D insufficiency has an important role in the early treatment of MS.”
As they state, trials underway should paint a more definitive and clearer picture on the role of vitamin D in slowing the progression of MS. Since this was an observational study, they can’t say for sure if vitamin D deficiency causes worse MS outcomes. However, observational research and some small experimental trials to date strongly suggest that vitamin D plays a role in the progression of MS and that supplementation may help.