Higher blood levels of vitamin D appear to offer some protection from multiple sclerosis. Swedish investigators analyzed blood samples from 1975 that had been collected from healthy people in northern Sweden. Most of the frozen samples were from pregnant women.
Nearly 200 of the women were diagnosed with multiple sclerosis years later. Each was matched to two others who had blood taken at the same time, but who did not develop multiple sclerosis. People with the highest levels of vitamin D were less than half as likely to develop multiple sclerosis compared to those with the lowest levels.