I have always found the parallels between ME and MS interesting. It has been known since 2009 that people with MS are infected, remotely infected or have transactivated EBV (HHV4). eg see: http://www.webmd.com/multiple-sclerosis/news/20090504/epstein-barr-virus-linked-to-ms Now with this study: http://www.prohealth.com/library/showarticle.cfm?libid=17171 The role of vitamin D and EBV is much clearer. If you look at many recent studies of vitamin D, the role of vit D in regulating infection and transactivation of viruses is very significant. Add to that the massive level of vitamin D deficiency present in the population of most Western countries this relationship is bound to go beyond that for MS. I have long thought that ME is such an illness and have long believed that vitamin D is playing a part in the onset. However, like MS, taking lots of vitamin D does not cure you but that does not negate the possible relationship, as we see in MS. As we know, their are many indicators of viral infection/activation: high turnover of neutrophils low NKC bright cell activity High RNase L fragmentation High levels of pro-inflammatory cytokines etc. However it will be difficult to tease out the re-activated viruses due to ME and the one or those that have caused it. Moral of the story for me is : It is urgent that governments solve the problem of vitamin D deficiency to try to prevent these illnesses. Fortifying milk is not an answer. Nor is expecting people to sunbathe. While sun is critical for health, people are too frightened of cancer, even though it is unlikely that melanoma is simply caused by too much sun. Melanoma is more likely caused by too little vitamin D when getting higher exposure to sun. The relationship between ME and Autism is also significant. Autism is also caused, at least in some by low levels of vitamin D. If you have ME and you have children or grandchildren makes damn sure their vitamin D levels are adequate (at least 50ng/ml of blood or higher). If you are pregnant or planning a child or have a daughter who is pregnant or planning a pregnancy, again make sure her vitamin D levels are at least 60ng/ml or higher.