Abstract
Multiple sclerosis (MS) is a relatively common debilitating neurologic disease that affects people in early adulthood. While the characteristic pathology of MS has been well described, the etiology of the disease is not well understood, despite decades of research and the identification of strong genetic and environmental candidates for susceptibility. A question central to all diseases, but posed specifically for MS at the XVI European Charcot Foundation Lecture, was 'Can MS be prevented?' To address this question, we have evaluated the available data regarding nutritional and environmental factors that may be related to MS susceptibility and suggest the extent to which a potential intervention may reduce disease burden. It is our opinion that intervention, particularly supplementation with vitamin D, could have a dramatic impact on disease prevalence. Understanding that any intervention or behavioral modification will surely act in the context of genetic susceptibility and unidentified stochastic events, it is likely that not all MS is 'preventable'. Epidemiologic observation has provided key insights into environmental and nutritional factors that may alter one's susceptibility to MS, however, there are still many questions in unraveling the etiology of this complex disease.