By Marc Sorenson, EdD. Sunlight institute… sun exposure
If only those who suffer from MS had known the truth when they were younger! Getting plenty of sun exposure might have saved them from the ravages of this horrible disease. Much has been written about the influence of vitamin D on MS, and in this blog, I have pointed out that sun exposure may be more important than vitamin D. A new study conducted in Australia, and presented at the 32nd Congress of the European Committee for Treatment and in MS in Research in London, England, is interesting in the way it was conducted.
By questionnaire, the researchers used past and present sun exposure as a surrogate for vitamin D levels and concluded that historical, but not current, vitamin D levels protect against MS.
This was an erroneous procedure to measure the influence of vitamin D levels on MS. It has already been established that sun exposure per se may be the operative habit that protects against MS. And in my opinion, vitamin D levels may only be surrogates for sun exposure, not vice versa. And, sun exposure probably mitigates MS, independent of vitamin D.
One of the most compelling papers on sun and MS was produced by Dr. Robyn Lucas and colleagues. Here are the salient points in their report called Ultraviolet radiation, vitamin D and multiple sclerosis:
- There is strong evidence from observational studies that low past sun exposure is associated with an increased risk of developing multiple sclerosis (MS).
- Lower sun exposure or lower vitamin D status have been linked to more severe MS, that is, more frequent relapses and more rapid progression to disability.
- Vitamin D supplementation trials for people with MS have shown improvement in immunological and MRI parameters, but with little convincing evidence of clinical benefit.
- Higher levels of sun exposure may have benefits for MS-related immune parameters through both vitamin D and non-vitamin D pathways.
- Exposure to ultraviolet radiation may result in immune tolerance that is beneficial for MS through upregulation of T and B regulatory cells, enhanced levels of cis-urocanic acid, alterations in dendritic cell trafficking as well as release of a range of other cytokines and chemokines.
To elucidate the last paragraph it is necessary to understand the vocabulary used. T cells are an integral part of the immune system that help rid the body of invading microorganisms. The regulatory T cells (or suppressor T cells) are a subpopulation of T cells which modulate the immune system and help prevent the body from attacking itself. MS is another autoimmune disease in which the body is attacked its own immune system, which in the case of MS, destroys the myelin sheath. The regulatory, or T suppressor cells suppress these attacks, thereby preventing, abrogating or ameliorating the disease. B regulatory cells are also a part of the immune system and can, through their suppressive functions decrease inflammation, possibly through the production of anti-inflammatory cytokines. Cis-urocanic acid is a chemical that is significantly lower in MS patients, and when stimulated by sun exposure, significantly reduces many indicators of MS.  Dendritic cells are also messenger T cells that are essential in assisting sun exposure to decrease the immune response that effects autoimmune diseases.
So let’s hear it for sun exposure as the very best therapy for MS. Be safe and don’t burn, and don’t use sunscreens, which can negate 99% of the sun’s vitamin D production.
 Robyn M Lucas, Scott N Byrne, Jorge Correale, Susanne Ilschner & Prue H Hart. Ultraviolet radiation, vitamin D and multiple sclerosis. Neurodegener. Dis. Manag 2015 (epub ahead of print).
https://en.wikipedia.org/wiki/Regulatory_T_cell (accessed November 24, 2015.)
 Min Yang, Ke Rui, Shengjun Wang and Liwei Lu. Regulatory B cells in autoimmune diseases. Cellular & Molecular Immunology (2013) 10, 122–132. Cellular & Molecular Immunology (2013) 10, 122–132.
 Jorge Correale and Mauricio Farez.S60 Multiple Sclerosis: Biomarkers: Clinical Phenotype Immune System Modulation in Multiple Sclerosis as a Result of Sun exposure: Role of cis-Urocanic Acid. Neurology April 6, 2012. (names s
 Correale J, Farez MF. Modulation of multiple sclerosis by sun exposure: role of cis-urocanic acid. J Neuroimmunol. 2013 Aug 15;261(1-2):134-40.
 Breuer J, Schwab N, Schneider-Hohendorf T, Marziniak M, Mohan H, Bhatia U, Gross CC, Clausen BE, Weishaupt C, Luger TA, Meuth SG, Loser K, Wiendl H. Ultraviolet B light attenuates the systemic immune response in central nervous system autoimmunity. Ann Neurol. 2014 May;75(5):739-58.