Vitamin D levels low in African-Americans with multiple sclerosis

Sample size 700 - comparing people with and without MS.  Found that 77 percent of MS patients have vitamin defciency.   The people with MS were exposed to a lower monthly UV index (average of 3.8) than those without the disease (average of 4.8). They also lived an average of about one degree of latitude farther north than those without the disease.

http://esciencenews.com/articles/2011/05/23/vitamin.d.levels.low.african.americans.with.multiple.sclerosis