This is part 2 of Who Gets MS? Have you arrived here first and want to read from the beginning? If you'd like to read part 1 first, click here.
As far as who gets multiple sclerosis and where they live, there is a definite pattern. This fact has been know for quite a long time. The general rule is the colder the climate, the more cases of MS there will be. So the farther away from the equator, the more likely you are to develop MS. This fact has been linked to vitamin D levels.
Do your remember learning about latitude and longitude in geography? Well if you do, then you know that the latitude lines run around the earth the way the equator does. If you were to draw a line right around the 37th parallel or 37 degrees north of the equator, you would see twice as many cases of MS above the line as there are below it.
So the southern states like Florida, Georgia, Mississippi, Alabama, Texas, New Mexico, and Arizona, would have very few cases of MS. Where as in states like Virginia,Kentucky, Missouri, Kansas, Colorado, Utah, and Nevada, the number of cases would begin to rise. When you reach Canada, there are twice as many incidences of MS than there are in the US.
When you look around the world above the 37 degree north and below 37 degree south, Northern Europe into the USSR, New Zealand and southeastern Australia, you see high rates of MS.
There were large studies done in Israel and South Africa where records were kept of people who had MS. In Israel scientists recorded every case of MS, including how old they were when they developed MS, where they came from and how old they were when they migrated.
One major fact that came out of the studies was that if someone immigrated before the age of 15, they had the same lower risk of developing MS as the native-born people. If they migrated after that age, then they had the same higher risk as the place from which they had migrated.
One of the reasons for this, could possibly be the link between levels of vitamin D and increased exposure to ultraviolet light in warmer climates. This could be a big factor in your development at a young age that lowers your risk of developing a disease like MS when you are older. Hmmm, something to think about.