In a small Canadian MS and vitamin D study presented to the American Academy of Neurology meeting in 2009, patients were given increasing doses of vitamin D to determine its safety at high dose. Apart from finding that high doses were safe (the higher dose group averaged 14,000IU per day through the study versus 1,000IU for the group treated with standard doses by their doctors), the researchers found that the higher dose group had 2/3 fewer relapses through the course of the study. Further, measures of immune activity showed a shift in balance away from an inflammatory profile. This is very important data about multiple sclerosis and vitamin D. The magnitude of the benefit derived from taking vitamin D supplements at high dose was roughly twice as big as the effect of taking disease-modifying drugs like the interferons; and this was in comparison to taking a conventional dose of vitamin D. Had it been compared to taking placebo, the effect would almost certainly have been even bigger. This is compelling evidence that vitamin D supplements should be routinely prescribed for people with MS, and at a substantial dose.