Previous studies have demonstrated that levels of 25-hydroxyvitamin D are associated with inflammatory activity among patients with multiple sclerosis (MS). As the loss of gray matter volume predicts long-term disability among patients with MS, this study was designed to determine any association between 25-hydroxyvitamin D levels among patients with clinically isolated syndrome (CIS) and imaging measures of neurodegeneration.

Data were obtained from subjects in the STAy CIS trial, a randomized study of atorvastatin in patients with recent CIS, used to assess the association of 25-hydroxyvitamin D levels with imaging measures thought to reflect neurodegeneration. All subjects were evaluated clinically and by brain MRI at baseline and at months three, six, nine, and 12. The primary endpoint was the development of at least one MS relapse or at least three new T2 lesions on brain MRI at month 12. The data were reviewed for the relationship between 25-hydroxy vitamin D levels and clinical and MRI measures of inflammatory activity.

Of the 65 patients included in this study, 55% met the composite inflammatory endpoint, while 29% had a second attack during the follow-up period. Every 25 nmol/l higher 25-hydroxyvitamin D level was associated with a 7.8 mL higher gray matter volume (P＝0.025). A trend was noted for an inverse association between vitamin D levels and the composite endpoint of at least three new brain T2 lesions or at least one relapse within the first 12 months.

This study of patients with early CIS found that increased levels of 25-hydroxyvitamin D are associated with preserved gray matter volume.