A recent study discovered that vitamin D status is positively associated with gray matter volume in patients with multiple sclerosis.
Researchers recently evaluated the relationship between vitamin D status and gray matter to determine whether vitamin D has a neuroprotective effect for MS patients.
Multiple sclerosis (MS) is an autoimmune inflammatory condition that affects the central nervous system. It is characterized by the destruction of the insulating covers of nerve cells in the brain and spinal cord, known as myelin sheaths.
When an individual experiences their first neurological manifestation of MS, physicians diagnose them with clinically isolated syndrome (CIS). Those with CIS have a 50% chance of developing MS within a few years. Therefore, researchers have begun looking at factors that may lead to the development of MS with the aim to prevent this disease from taking place.
Gray matter, which contains the majority of the brain’s neuronal cell bodies, is responsible for processing information in the brain. Research has shown that reductions in gray matter volume reflect neurodegeneration and disability in patients with MS.
Studies have provided accumulating evidence supporting the relationship between low vitamin D levels are MS. According to one study, researchers found that people with genetically low vitamin D levels are more likely to have MS compared to those who are not genetically predisposed to low vitamin D levels. Other research has also found that vitamin D may help protect against the development of MS and provide a treatment effect for those with either MS or CIS.
Despite the established relationship between vitamin D and MS, along with that of gray matter volume and MS disability, no studies to date have been conducted to determine if vitamin D may play a role in gray matter volume among patients with MS. Therefore, researchers compared 25(OH)D levels in 65 CIS patients to their normalized gray matter and brain parenchymal volumes via brain MRI. A lower brain parenchymal volume is indicative of brain atrophy, or a loss of neurons and the connections between them.
Data was gathered as a subset of the levTAyCIS study, which was a randomized, double blind, multicenter, placebo-controlled trial comparing daily administration of atorvastatin (a cholesterol lowering medication) versus placebo for the treatment of CIS. This study was terminated early due to the low recruitment number. The patients had their 25(OH)D measured either at baseline or at their 6 month visit. They also received a brain MRI, which the researchers used to evaluate gray matter and brain parenchymal volume.
The researchers found that, of the 65 CIS patients, each 25 nmol/l (10 ng/ml) increase in 25(OH)D was associated with a 7.8 ml rise in grey matter volume (p = 0.025). Low vitamin D status was associated with a 44% increased odds of new brain lesions and relapse within a year; though, this was not statistically significant (p=0.096).
The researchers concluded,
“Vitamin D status may impact neurodegeneration after CIS, although these results should be replicated in a second study. If confirmed in clinical trials, vitamin D supplementation may reduce long-term disability.”
They went on to state,
“If supplementation with vitamin D does preserve gray matter with a similar degree of magnitude over the same time frame, then increasing a person’s 25-hydroxyvitamin D levels by 87 nmol/l, a feasible goal, would be associated with nearly 3% less reduction in gray matter volume over 18 months. Such an effect size would suggest that vitamin D supplementation would be quite impactful in reducing clinical disability in MS patients.”
This is the first study to have found a link between vitamin D status and gray matter volume, providing a potential explanation for the role of vitamin D in the prevention or treatment of MS. However, there were a couple of limitations to this study. The small sample size, relatively short duration and limited outcome occurrence led to wide confidence intervals, which may have resulted in missed associations.
The researchers call for longer duration, larger scaled clinical trials in order to determine if vitamin D may help prevent long term MS related disability or maintain neuronal integrity.
Sturges, M. & Cannell, JJ. Closer look: vitamin D may help protect the brain in MS patients. The Vitamin D Council Blog/Newsletter, November 24, 2015.