Vitamin D is very important to us. Unlike many other vitamins, vitamin D is produced in our own body as a response to sunlight. Vitamin D is praised for its health benefits, but they are not fully understood. Scientists from the University of Edinburgh found that the vitamin D might influence susceptibility to diseases such as multiple sclerosis.
Vitamin D is produced in human body as a response to exposure to sunlight. Image credit: Alex Proimos via Wikimedia (CC BY 2.0)
Vitamin D plays a role in our immune system. In fact, it affects key cells of our immune system – it helps dendritic cells’ ability to activate T cells. T cells, of course, help us to fight off infections, but in people with various autoimmune diseases, such as the multiple sclerosis, they start attacking body’s own tissues, causing a lot of trouble. Scientists understood that this means that vitamin D is also playing a role in autoimmune disease, but what that role is? And what kind of effect would vitamin D deficiency have for people who suffer from such conditions like multiple sclerosis?
Scientists studied cells from mice and people and found vitamin D caused dendritic cells to produce more of a molecule called CD31 on their surface. This hindered the activation of T cells. In order for the T cell activation to be completed, two different types of immune system cells have to come in contact. This is prevented by CD31 build-up on the surface of dendritic cells. This means that immune reaction is reduced by vitamin D, but it is not a bad thing. In this way our body regulates immune system, making sure that it is in check and not too harsh on native tissues. Scientists say that this makes sense and goes along previously identified risk factors for autoimmune diseases.
Vitamin D deficiency damages immune system – this was known before. It means that exposure to sun is crucial for maintaining a healthy immune system and preventing autoimmune diseases. Professor Richard Mellanby, one of the authors of the study, said: “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”. Hopefully, scientists will continue these studies and will find new ways to use vitamin D to improve human health.
Humans are designed to stay outside for a significant portion of the day. We need vitamin D and it does a lot of good for our health. However, we are still trying to understand how it affects our immune system. In the future studies like this could actually contribute to new treatments for conditions like multiple sclerosis and other autoimmune diseases.
Source: University of Edinburgh