Vitamin D status and antibody levels to common viruses in pediatric-onset multiple sclerosis

Background: The relative contribution and interaction of risk factors for multiple sclerosis (MS) have not been evaluated. Objectives: To determine whether vitamin D status is associated with antibody levels to common viruses in pediatric-onset MS or clinically isolated syndrome (CIS) patients and controls. Methods: We assessed whether vitamin D status was associated with viral antibody levels to Epstein-Barr virus, cytomegalovirus (CMV), and herpes simplex virus (HSV)-1 or -2 in subjects who demonstrated evidence of remote infection with these viruses and whether these associations differed depending on disease status. Results: In 140 subjects, vitamin D status was weakly associated with antibody levels to CMV but not to the other viruses. However, there were some interactions between vitamin D status and disease state. Among those with vitamin D sufficiency (>= 30 ng/ml), MS/CIS patients had higher antibody levels to Epstein-Barr nuclear antigen-1 than controls. Vitamin D sufficiency was associated with higher CMV antibody levels in MS/CIS subjects but lower CMV antibody levels in controls. Higher vitamin D levels appeared to be associated with higher titers to HSV-2 in MS/CIS patients but not controls. Conclusions: Vitamin D status may be differentially associated with antibody levels to common childhood viruses among seropositive subjects.