Intrathecal levels of vitamin D and IgG in multiple sclerosis.

BACKGROUND: Intrathecal synthesis of IgG is a hallmark of multiple sclerosis (MS). Vitamin D may modulate B-cell function and dampen the synthesis of IgG. OBJECTIVE: To investigate the relation between vitamin D levels in cerebrospinal fluid and serum and intrathecal synthesis of IgG. METHODS: 25-hydroxyvitamin D (25(OH)D) and IgG were assessed in cerebrospinal fluid and serum in 40 patients with MS. RESULTS: There was no significant correlation between the IgG index and 25(OH)D levels in cerebrospinal fluid or serum. The levels of 25(OH)D in cerebrospinal fluid and serum did not differ between patients with and without intrathecal synthesis of IgG. There was a non-significant trend towards a positive correlation between the concentrations of 25(OH)D and IgG in the cerebrospinal fluid, but not in serum. CONCLUSION: Physiological variation in vitamin D does not exert a major impact on intrathecal synthesis of IgG in MS.