Research finds vitamin D helps prevent multiple sclerosis

SAN FRANCISCO Researchers have found evidence that a direct interaction between vitamin D and a common genetic variant alters the risk of developing multiple sclerosis. The research, published Friday in the open-access journal PLoS Genetics, suggests that vitamin D deficiency during pregnancy and the early years may increase the risk of the offspring developing MS later in life.

"Our study implies that taking vitamin D supplements during pregnancy and the early years may reduce the risk of a child developing MS in later life," stated lead author Sreeram Ramagopalan. "Vitamin D is a safe and relatively cheap supplement with substantial potential health benefits. There is accumulating evidence that it can reduce the risk of developing cancer and offer protection from other autoimmune diseases."

The researchers found that proteins activated by vitamin D in the body bind to a particular DNA sequence lying next to the DRB1*1501 variant, in effect switching the gene on.

"In people with the DRB1 variant associated with MS, it seems that vitamin D may play a critical role," stated co-author Julian Knight. "If too little of the vitamin is available, the gene may not function properly."

"We have known for a long time that genes and environment determine MS risk," stated Professor George Ebers, University of Oxford. "Here we show that the main environmental risk candidate – vitamin D – and the main gene region are directly linked and interact."

MS is the most common disabling neurological condition affecting young adults. More than 85,000 people in the United Kingdom and 2.5 million worldwide are thought to suffer from the condition, which results from the loss of nerve fibres and their protective myelin sheath in the brain and spinal cord, causing neurological damage.

The causes of MS are unclear, but it has become evident that both environmental and genetic factors play a role. Previous studies have shown that populations from Northern Europe have increased MS risk if they live in areas receiving less sunshine. This supports a direct link between deficiency in vitamin D, which is produced in the body through the action of sunlight, and increased risk of developing the disease.PLoS Genetics is published by the Public Library of Science, a non-profit organization of scientists and physicians committed to making the world's scientific and medical literature a freely available public resource.