Since we raise funds for Multiple Sclerosis research and advocacy through the Carolina Century and as the Roadskater.net cycling and inline skating team, we often are asked about the disease. We've tried to learn more about it, but it can be difficult to explain in a few words. One of our sidebars on this site tracks MS research, and usually the articles are either inconclusive or incomprehensible.
This article is pretty good, especially in the last three paragraphs, which explain MS generally. It's worth a read as a backgrounder, and for the information on the Vitamin D as a factor in MS development. The first comment to the article also seems knowledgeable, and the recommendation for Vitamin D from sunlight sounds good...but I think I may need to add some vitamins in with that.
63° 49' 33.0492" N, 20° 15' 46.926" E