Vitamin D
New Directions in MS Research: New Therapeutic Approaches
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Perhaps no nutrient has been the subject of more MS-related research than Vitamin D. This focus arose in part from the observation that the prevalence of MS is higher in northern latitudes, where exposure to the sun – which facilitates the body’s production of vitamin D – is limited. As more and more research demonstrated the immune-related benefits of Vitamin D, efforts to determine whether the nutrient protects against MS intensified.
One of the latest studies pursuing these questions comes from Sweden, where investigators analyzed blood samples from 666 people who later developed relapsing MS and from 666 healthy controls matched to the people with MS in terms of age, sex, and other factors. All of the blood samples from MS patients were collected before the people developed symptoms and before they reached 40 years of age.87
An analysis of Vitamin D levels in participants’ blood samples found that those with the highest concentrations of Vitamin D had a significantly lower risk of developing MS compared with people with lower concentrations. This effect was more pronounced in younger adults than in older adults. The researchers noted, “This study lends further support to the hypothesis that vitamin D may be protective against MS.” 87
Further support for the protective benefits of Vitamin D comes from extended follow-up of 278 people with clinically isolated syndrome (CIS), a common precursor to MS.88 A recently reported study examined long-term cognitive status in CIS patients who had participated in the BENEFIT (Betaferon/ Betaseron in Newly Emerging Multiple Sclerosis for Initial Treatment) clinical trial, and who had undergone 11 years of follow-up. After assessing a number of potential factors, researchers found that higher levels of 25-OH Vitamin D, a biomarker for Vitamin D concentrations, predicted better cognitive function. Smoking, meanwhile, predicted worse cognitive function over the long term.88
Another study examined whether adding a high-dose Vitamin D supplement to interferon beta-1b therapy would affect the number of central nervous system (CNS) lesions found on MRI in people with relapsing multiple sclerosis (RMS).89 The randomized, doubleblind trial involved 53 people. Twenty-eight of those patients received 20,400 IU of cholecalciferol, a Vitamin D supplement, every other day for 18 months, while 25 participants received of 400 IU cholecalciferol, also given every other day for 18 months. The primary endpoint of the study was the cumulative number of new hyper-intense T2 lesions after 18 months compared to baseline. Secondary endpoints were safety, T2-lesion volume, disability progression, and annualized relapse rate, or ARR.
At the study’s completion, researchers analyzed data on 38 patients who fulfilled the protocol for the trial. Twenty-one of those people were in the high-dose arm; 17 were in the low-dose arm. Serum levels of 25-OHVitamin D increased in both groups over 18 months, more than tripling from 18 ng/ml to 65 ng/ml in the high-dose group and rising from 16 ng/ml to 24 ng/ml in the low-dose group. However, the change in cumulative number of new lesions over 18 months was not significantly different between the study arms. The median T2-lesion count in the highdose arm rose from 42 at baseline to 46 in the high-dose arm, while that number rose from 64 to 70 in the low-dose arm. Meanwhile, 44 adverse events were recorded in the highdose arm versus 34 in the low-dose arm. Importantly, however, no serious adverse events related to Vitamin D were recorded.
In examining the study findings, researchers concluded, “High-dose supplementation increased serum 25-OHVitamin D to sufficient levels with no positive effect on the cumulative number of new T2 lesions. Supplementation with high dose Vitamin D (20.400 IU) as an add-on therapy to IFN β is safe and tolerable in RRMS patients.”89
The study and its results examined an important question – whether the protective benefit against developing MS seen with higher blood levels of Vitamin D could be translated into an effective strategy for reducing the number of CNS lesions in people who already have MS. While the results were disappointing, they underscore the complexity of the MS disease process and add significantly to investigators’ knowledge base.