Proper eatig habits, that's the rub. What is conventionally considered as healthy or proper can be tramautic for an individual predisposed to MS.
I contend that most ilnesses are preventable. Of course it is difficult to prove the effectiveness of a preventative therapy but read on. This paper
discusses how migrants from a high MS prevalent area reduced their prevalence by as much as 75% by moving to a sunnier climate.
Was it vitamin D or some other factor that can be held accountable for this success? By considering the known immunoregulatory properties
of vitamin D it certainly is plausible that even incidental sun exposure in a tropical area could provide enough vitamin D to act as a protective feature.
Consider too this recent Harvard study
which found a preventative effect from MS of only 400 IU/d of vitamin D.
There's much more of course but you be able to envision that corroboration of many different sources of evidence paint a compelling reason to consider vitamin D as an effective preventative measure.