UVB radiation, vitamin D and multiple sclerosis

作者：DeLuca H F^*; Plum L

来源：Photochemical and Photobiological Sciences, 2017, 16(3): 411-415.

DOI：10.1039/c6pp00308g

Acheson et al. (1960) observed an inverse relationship between sunlight exposure and the incidence of Multiple Sclerosis (MS). This led to the suggestion that increased levels of vitamin D caused by sunlight in some way suppresses MS. Further, super physiological doses of the metabolically active metabolite of vitamin D, i. e. 1 alpha, 25 dihydroxy vitamin D suppresses the animal model of MS i. e. experimental autoimmune encephalomyelitis (EAE). However, this response was accompanied by hypercalcemia. Hypercalcemia itself can suppress EAE. The ability of 1,25(OH)(2)D-3 to suppress EAE in mice is largely eliminated by a low calcium diet until hypercalcemia is induced by high doses of 1,25(OH)(2)D-3 that causes mobilization of calcium from the skeleton. Of great importance is the finding that vitamin D deficiency prevents EAE, a finding dramatically opposite to the original hypothesis. Further, vitamin D receptor knock out animals do not develop EAE supporting the idea that vitamin D does not suppress EAE. Upon revisiting the inverse relationship between light exposure and incidence of MS, a narrow band of light (300-315 nm) was discovered that prevents EAE without a change in serum levels of 25 hydroxy vitamin D (indicator of vitamin D status). Clinical trials are underway to explore the possible use of this narrow band light as a treatment to stop the progression of MS, while biochemical studies are underway to evaluate the mechanism of action of the narrow band light.

• 出版日期2017