Surveys of patients with multiple sclerosis (MS) report that most are interested in modifying their diet and using supplements to potentially reduce the severity and symptoms of the disease. At the present time, however, the only vitamin with sufficient evidence to support routine supplementation for patients with MS is vitamin D, according to a recent review. Therefore, it is important for clinicians to know which supplements their patients are taking and to educate them on any known efficacy data, along with any potential medication interactions and adverse effects of individual supplements. Given that dietary supplements and vitamins are not subject to the same regulatory oversight as prescription pharmaceuticals in the US, it is recommended that vitamins and supplements be purchased from reputable manufacturers with the US Pharmacopeia designation.