27/08/2015 10:15 BST | Updated 25/08/2016 06:59 BST

What's Vitamin D Got to Do With MS?

Vitamin D is something that the conversation just keeps coming back to. How do we make sure we get enough, and is a deficiency going to make us ill? I see links being made between vitamin deficiencies and different conditions all the time, and I'm particularly interested in the link to multiple sclerosis (MS).

MS is incurable and affects more than 100,000 of us in the UK. It can cause sight loss, pain, incontinence, fatigue and disability.

We don't know what causes MS, but it's likely to be a complex link between genetic and environmental factors. So far, research has flagged up viruses, smoking and vitamin D as triggers that could affect your risk.

The possible link between MS and vitamin D came about because MS is more common further away from the equator (where there's less sunshine). We get most of our vitamin D from sunlight, when the vitamin is made under the skin.

Research shows that a lack of vitamin D in early childhood or before birth might increase the risk of developing MS later in life. Interestingly some studies have uncovered a potential 'month of birth' effect; people born following winter months seem to have a higher risk of developing MS later in life, compared to people born following summer months (with more sunshine). But it's a rather contentious area of research, with some experts arguing that this effect is only seen because of other factors, like varying birth rate.

It looks like MS has a connection with the sunshine vitamin, and research published this week in the journal Public Library of Science Medicine brings us an exciting step closer to understanding the biological nature of that connection. The new study, led by researchers at McGill University, Canada, suggests a causal link for the first time - showing that people who are genetically predisposed to having low vitamin D levels are more likely to develop MS.

Could this information be used to help prevent MS in the future, or could vitamin D supplements be a treatment for people that have MS already? Both of these questions are in our top ten research priorities, decided by healthcare professionals and people with MS.

We've set up the UK MS Clinical Trials Network with a group of healthcare professionals, people affected by MS and researchers with one united aim - to develop innovative clinical trials for the treatment of MS. One thing the network is looking specifically at is vitamin D. There isn't enough evidence to tell us if vitamin D is a safe and effective treatment for MS yet and trials to date have been small and incomparable, but this group hopes to change that. They've commissioned a review of all of the literature to date and are scoping out new and innovative trial designs that could help us solve the mystery.

At the MS Society we're working hard to get the answers we need, and we won't stop until we end MS.