There is a relatively high use of complementary and alternative medicine (CAM), especially dietary supplements, among people with multiple sclerosis (MS). Health professionals with CAM information can improve the quality of patient care by guiding patients away from possibly harmful therapies and, if appropriate, towards low-risk, possibly effective therapies. Dietary Supplements and Multiple Sclerosis is meant to be referred to when people with MS ask a question about a particular dietary supplement. Supplements are arranged in alphabetical order under the most commonly used name. In addition, the index contains a listing of these common names as well as less common names that may be encountered. The main information about the supplements is written in a concise summary form that usually discusses only the MS relevance of the supplement. The supplements selected for inclusion are those with specific MS relevance, such as those that are known to be used by people with MS, have claimed efficacy for slowing disease progression or relieving MS symptoms, interact with drugs commonly used to treat MS, and potentially worsen MS or its symptoms. Also, supplements are reviewed that are popular in the general population or are known to have serious adverse effects.