The way I see it...
If someone finds a simple natural food or nutrient that fixes a problem for them, go for it. It's almost always harmless, cheaper than prescription stuff, and might do some good. When it comes right down to it, even a placebo that relieves symptoms can be considered a success.
I've been tracking things like Vitamin D and some others for MS, but so far, Vitamin D results seem to relate more to keeping someone from getting it in the first place (a Vitamin D connection would explain some of the odd demographics of MS sufferers).