- An inverse relationship appears to exist between vitamin D3 status and the probability of developing MS. Vitamin D3 supplementation may be a possible therapy in MS.
- A Phase I/II trial of high-dose oral vitamin D3 with calcium trial showed that high-dose Vitamin D3 - 10,000 IU/day or higher - is safe and tolerable, with some evidence of clinical improvement. More data are needed.
- An Australian study found that people with CIS had less cumulative skin damage caused by the sun than controls, suggesting that they had less sun exposure. In a Canadian study of children who had experienced a single neurologic episode, the 16 percent who went on to develop MS had significantly lower vitamin D levels than those who did not.
- Evidence is beginning to accumulate of a complex interaction between genetic susceptibility to MS and the role of vitamin D. The risk of developing MS is three times higher among those who carry a single copy of a specific gene variant and 10 times higher in those carrying two copies of the gene, which appears to be involved in the immune system. Proteins activated by vitamin D bind to and alter the function of a section of the chromosome near this gene, suggesting that vitamin D deficiency during pregnancy might alter the function of fetal genes, predisposing children to MS. The gene contains a "switch" that is activated by one form of vitamin D; it was missing from the variants not associated with MS.