Their results, reported at the American Academy of Neurology meeting, held earlier this month, indicated that:
- The majority of MS patients and healthy controls had insufficient vitamin D levels.
- Clinical evaluation and magnetic resonance imaging (MRI) images show low blood levels of total vitamin D and certain active vitamin D byproducts are associated with increased disability, brain atrophy and brain lesion load in MS patients.
- A potential association exists between cognitive impairment in MS patients and low vitamin D levels.
The MRI study involved 236 MS patients — 208 diagnosed with the relapsing-remitting type and 28 with secondary progressive, a more destructive form of MS — and 22 persons without MS.
All participants provided blood serum samples, which were analyzed for total vitamin D (D2 and D3) levels as well as levels of active vitamin D byproducts. MRI scans performed within three months of blood sampling were available for 163 of the MS patients.
Results showed that only seven percent of persons with secondary-progressive MS showed sufficient vitamin D, compared to 18.3 percent of patients with the less severe relapsing-remitting type.
Higher levels of vitamin D3 and vitamin D3 metabolism byproducts (analyzed as a ratio) also were associated with better scores on disability tests, results showed, and with less brain atrophy and fewer lesions on MRI scans.