Recent studies and commentaries link vitamin D with several autoimmune diseases, including multiple sclerosis (MS). Adequate vitamin D intake reduces inflammatory cytokines through control of gene expression, thus inadequate vitamin D intake is suggested as a mechanism that could contribute to inflammation and, consequently, development of MS. Poor vitamin D status has been associated with increased risk for development of MS, and patients with MS may suffer consequences of vitamin D deficiency, such as bone loss. Animal studies and very limited human data suggest possible benefit from vitamin D supplementation in patients with MS. Based on the current state of research, a key principle for practicing dietetics professionals is to include vitamin D status in nutritional assessment. For those at risk for poor vitamin D status, intake can be enhanced by food-based advice and, when indicated, vitamin D supplementation.