University of Buffalo

Early last month, we came across a study that revealed Vitamin D to be essential in triggering immune defenses. Studies connected at the University of Buffalo have now shown that low vitamin D levels may be associated with more advanced physical disability and cognitive impairment in individuals with multiple sclerosis.

Neurologists indicate that a large number of MS patients and healthy controls appeared to have insufficient levels of Vitamin D. Low blood levels of total vitamin D and certain active vitamin D byproducts were found to be related with augmented disability, brain atrophy and brain lesion load in MS patients. This was ascertained through clinical evaluation and MRI images. There appeared to have been a potential link between cognitive impairment in MS patients and low vitamin D levels.

For the MRI study, 236 MS patients were roped in. Among them, 208 were diagnosed with the relapsing-remitting type and 28 were identified with secondary progressive. The latter is known to be a more destructive form of MS. 22 persons without MS were also involved in the analysis. Blood serum samples of all the participants were investigated for total vitamin D (D2 and D3) levels in addition to levels of active vitamin D byproducts. Within three months of blood sampling, MRI scans were available for 163 of the MS patients.

The results pointed that only seven percent of persons with secondary-progressive MS exhibited sufficient vitamin D. This was in comparison to 18.3 percent of patients who had the less severe relapsing-remitting type. On the disability tests, increased levels of vitamin D3 and vitamin D3 metabolism byproducts that was analyzed as a ratio were also associated with better scores. This was along with lower brain atrophy and fewer lesions on MRI scans.

Bianca Weinstock-Guttman, MD, UB associate professor of neurology/Jacobs Neurological Institute and director of the Baird Multiple Sclerosis Center, is first author on the study, commented “Clinical studies are necessary to assess vitamin D supplementation and the underlying mechanism that contributes to MS disease progression.”

Vitamin D status that may be lower than normal is apparently associated with a higher risk of developing MS. However, there appears to be very little information about its link with cognitive impairment. Sarah A. Morrow, MD, UB assistant research professor of neurology/Jacobs Neurological Institute and lead author on the cognitive-impairment study tried to gain a better understanding of this. She examined in contrast vitamin D levels in blood samples of 136 MS patients with the outcomes of their neuropsychological assessments that quizzed multiple types of cognition affected by MS.

“Results showed that MS patients who were impaired on tests of executive function –critical reasoning and abstract thinking — and the ability to plan and organize, were more likely to be deficient in vitamin D,” said Morrow. “This relationship held true when controlling for the season during which vitamin D was measured, as well as depression, which is known to be associated with lower vitamin D levels.”

Morrow observed that when vitamin D levels are not sufficient, verbal fluency and visual-spatial memory may also have a higher likelihood of being affected. Morrow is carrying on her investigation to clarify these associations.

These results have been reported at the American Academy of Neurology meeting.