MS Frontiers 2022 | The developing role of vitamin D and sun exposure in multiple sclerosis onset and clinical course

Steve Simpson-Yap, PhD, MPH, University of Melbourne, Melbourne, Australia, comments on an emerging topic in the field of multiple sclerosis (MS): vitamin D and sun/UV exposure. There have been multiple investigations looking at sun exposure across the life course and vitamin D levels prior to MS onset and during disease, with some showing associations with relapse rates. The Ausimmune case-control study (Australian Multi-centre Study of Environment and Immune Function) also suggested that low sun exposure and vitamin D deficiency are independent risk factors for MS onset. The wealth of observational data and indirect evidence from the recognized latitudinal gradient of MS (i.e., MS frequency increases with distance from the equator) implies that these factors are important, yet vitamin D supplementation has been trialed and showed little to no effect. Hence, the current recommendation for patients is to not supplement vitamin D or increase sun exposure above what is expected for general health because the evidence is not strong enough to say otherwise. This interview took place at the MS Frontiers 2022 congress in Swansea, UK.