Vitamin D deficiency linked to multiple sclerosis

While no specific cause of multiple sclerosis (MS) has yet to be determined, research has shown that vitamin D, which the body produces as a result of exposure to sunlight, may help control a gene that is known to increase the risk of MS.  In the study, scientists from the University of British Columbia and University of Oxford conducted research on a section of the genome on chromosome six that has been shown to have the greatest impact on increasing the risk of MS. In fact, one in 300 people living in the UK who carries a single copy of the gene variant DRB1*1501 - and one in 100 who carries two copies - are likely to develop MS. In a normal population, just one in 1,000 will develop the condition.

The researchers discovered that when proteins are activated by vitamin D, they bind to a particular DNA sequence located next to DRB1*1501. This alters the gene's function.

One reason could be due to an effect on the thymus, the part of the immune system that produces T cells to protect the body against bacteria and viruses. In people who carry DRB1*1501, vitamin D deficiency early on in life can impact the ability of the thymus to detect "rogue" T cells. When those cells are allowed to continue attacking the body, it can result in the loss of the protective myelin sheath in the brain and spinal cord. This can cause neurological damage.

Co-author, Professor George Ebers, from the Wellcome Trust Centre for Human Genetics, at the University of Oxford, notes that "we show that the main environmental risk candidate - vitamin D - and the main gene region are directly linked and interact." And he suggests that supplements of vitamin D taken during pregnancy and during the child's early years could help reduce the risk of developing MS later on in life.

And adds Simon Gillespie, chief executive of the MS Society, "These remarkable results tie together leading theories about the environment, genes and MS but they are only part of the jigsaw. This discovery opens up new avenues of MS research and future experiments will help put the pieces together."

News Release: Vitamin D helps control MS gene  http://news.bbc.co.uk/2/hi/health/7871598.stm February 5, 2009