Researchers have discovered direct evidence that shows vitamin D may help control the genes that trigger multiple sclerosis.

In a new study, published in the journal PLoS Genetics, researchers say they've found a direct link between vitamin D and a gene variant, known as DRB1*1501, that is susceptible to MS.

Prof. George Ebers, with the University of Oxford, said researchers have known for a long time that genes and environment determine MS risk.

"This is the first evidence that the environment, in the form of vitamin D, is directly related to the gene region that gives you the major risk for MS," Ebers told CTV News.

The study, funded in part by the MS Society of Canada, 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.

If there isn't enough vitamin D available in the body, the DRB1*1501 gene may not function properly.

In the U.K., one in 1,000 people are likely to develop MS but the chance increases to one in 300 among those carrying a single copy of the DRB1*1501 gene variant.

The chance increases to one in 100 among those carrying two copies.

Around the world, 2.5 million people suffer from MS, which results from the loss of nerve fibres and their protective myelin sheath in the brain and spinal cord, causing neurological damage.

Previous studies have shown that people who live in areas receiving less sunshine have an increased risk of developing MS as sunlight produces vitamin D in the body.

The lead author of the recent study, Dr. Sreeram Ramagopalan, said Thursday that the new research "implies that taking vitamin D supplements during pregnancy and the early years may reduce the risk of a child developing MS in later life,"

Ebers said he'd like to see all women taking vitamin D while pregnant.

"The evidence is strong that vitamin D is very important in early development of the fetus," he said.

Levi Barron developed MS around the age of 12. Now 16, Levi has responded to treatment and is "pretty much ok," says his mother, Karen.

She said they now both regularly take vitamin D.

"It's quite a little vitamin that's turning out to really knock everybody's socks off with where the research is going with it," Levi's mother, Karen, told CTV News.

Karen Barron said taking vitamin D was something she didn't think of during her pregnancy.

"I would strongly encourage any pregnant women to talk to their family doctor and find out what dosage of vitamin D they should be taking," she said.