Although MS was first described over 130 years ago, the exact cause(s) still remain a mystery, and there is no known cure. The term “multiple sclerosis” refers to two characteristics of the disease: the numerous affected areas of the brain and spinal cord producing multiple neurologic symptoms that accrue over time and the characteristic plaques or sclerosed areas that are the hallmark of the disease. MS is usually diagnosed in individuals between the ages of 20 and 45 years (although cases in children have been reported), with peak incidence occurring in the fourth decade.
There is an interesting apparent relationship between low levels of vitamin D, a weakened immune system, and increased incidence of multiple sclerosis. The incidence of MS is near zero in equatorial regions, where high sunlight exposure causes ample production of vitamin D through skin exposure. However, MS rates increase dramatically with latitude in both hemispheres. This has given researchers cause to suspect that environmental factors such as exposure to sunlight and the relationship between sunlight and vitamin D. Although the hypothesis that vitamin D3 is an immunoprotective environmental factor against MS is circumstantial, it is compelling and worthy of consideration.
Researchers from the University of California, San Francisco and SUNY Stony Brook Pediatric Multiple Sclerosis Center sought to determine if vitamin levels are associated with subsequent clinical relapses in pediatric-onset multiple sclerosis. The study included 110 pediatric subjects who had their serum 25-hydroxyvitamin D3 levels measured and were adjusted to reflect a deseasonized value. The patients were then followed for an average of 1.7 years during which the researchers recorded the number of relapses each patient experienced. The results revealed that an increase in vitamin D levels by 10 nanograms per milliliter of blood (ng/mL) corresponds with a 34% decrease in the rate of subsequent relapses. Therefore, raising the vitamin D level of a person with MS by 15 ng/mL which requires about 2,000 international units of vitamin D supplementation a day, could possibly cut a patient’s relapse rate in half. The researchers note that it is still not known whether vitamin D supplementation will be helpful in patients with MS, but since there appears to be a clear association between vitamin D levels and relapse rate there is strong rationale for conducting a clinical trial to measure the potential impact of supplementation. These findings are especially interesting because it indicates that it may be possible that vitamin D supplementation could have a profound impact on the course of this disease. The researchers also expect to see similar results in adult patients with MS.1
1 Mowry EM, Krupp LB, Milazzo M, et al. Vitamin D status is associated with relapse rate in pediatric-onset MS. Ann Neurol. 2010