Vitamin D deficiency said to influence susceptibility to multiple sclerosis

A new study by scientists at University of Edinburgh has shed light on the links between vitamin D deficiency and its influence on susceptibility to diseases such as multiple sclerosis.

It has long been known that our body produces vitamin D in response to sunlight. Researchers have found in previous studies that it also affects key cells of the immune system. The latest discovery could possibly explain how vitamin D regulates immune reactions that have been implicated in autoimmune diseases such as MS.

For the study, researchers at the University of Edinburgh focused on how vitamin D affects a mechanism in the body’s immune system – dendritic cells’ ability to activate T cells. It has long been known that in healthy people, T cells play a crucial role in helping to fight infections. In people with autoimmune diseases, however, they can start to attack the body’s own tissues.

By studying cells from mice and people, the researchers found vitamin D caused dendritic cells to produce more of a molecule called CD31 on their surface and that this hindered the activation of T cells. The team observed how CD31 prevented the two cell types from making a stable contact – an essential part of the activation process – and the resulting immune reaction was far reduced.

Researchers say the findings shed light on how vitamin D deficiency may regulate the immune system and influence susceptibility to autoimmune diseases. Low vitamin D status has long being implicated as a significant risk factor for the development of several autoimmune diseases. Our study reveals one way in which vitamin D metabolites can dramatically influence the immune system.

The study, published in Frontiers of Immunology, was funded by the Medical Research Council, Biotechnology and Biological Sciences Research Council, Natural Environment Research Council and Wellcome.