MS development not prevented by vitamin D supplements in people at high risk

  • A world-first clinical trial funded by MS Australia tested whether vitamin D supplements could prevent MS.
  • People with a first episode of demyelination who were not vitamin D deficient were treated with one of three doses of vitamin D or a placebo.
  • Vitamin D at any of the three doses did not prevent the onset of MS in the trial participants

Vitamin D supplements do not prevent the development of multiple sclerosis (MS).

That’s the finding from PrevANZ, a ground-breaking clinical trial funded by MS Australia to determine if oral vitamin D supplements can delay the onset of MS. The trial was conducted in people at high risk of MS who did not have a vitamin D deficiency.

The results of the trial will be presented for the first time at the 38th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) in Amsterdam.

Why test vitamin D in MS?

There has long been interest in the possible benefits of vitamin D supplements for those living with MS and whether they can be used to prevent the development of MS.

That’s because the risk of developing MS can vary depending on latitude, with those living furthest from the equator more likely to be affected by the disease.

In Australia, those living in the south of the country are seven times more likely to develop MS than those in the north. It has long been hypothesised that this is brought on by a lack of sunlight, which could potentially lower vitamin D levels.

MS Australia’s Head of Research, Dr Julia Morahan, said that given that vitamin D is readily available, there had been insufficient commercial interest in conducting this important research.

To ensure this vital work was undertaken, MS Australia sponsored this trial with the first participant enrolled in 2013,” Dr Morahan said.

What was the aim of the trial?

To test whether vitamin D can prevent MS, MS Australia, with support from MSWA, established the world’s first clinical trial involving 204 people from Australia and New Zealand.

A small, highly dedicated team worked for eight years on this study to establish the potential benefit of oral vitamin D supplementation to prevent new MS disease activity.

MS occurs when people have multiple instances of demyelination, or stripping away of the protective fatty outer layer, called myelin, around nerves in the brain and spinal cord.

So, for this trial, people who had experienced just one episode of demyelination of the brain or spinal cord were treated to see if vitamin D could prevent additional attacks or development of MS.

What did the researchers find?

Each person taking part in the trial was randomly assigned to one of three different daily doses of vitamin D (1000 IU, 5000 IU or 10000 IU), or a placebo (no vitamin D).

Vitamin D was used as a standalone therapy – the participants were not on other disease-modifying drugs for their MS.

Professor Helmut Butzkueven, Chair of the PrevANZ Steering Committee, said the participants were then followed for 48 weeks to determine whether they went on to develop MS.

We showed conclusively that doses of up to 10,000 units per day did not reduce MS activity compared to those who did not take vitamin D”, Professor Butzkueven said.

Professor Bruce Taylor, also from the PrevANZ Steering Committee, understands this might be seen as a disappointing result, but says it is a very important one.

We are now eagerly awaiting the results of D-LAY MS, a French study with very similar design”, Professor Taylor said.

There are more questions yet to be answered

The participants in this trial did not have vitamin D deficiency to begin with. We still don’t know whether people with vitamin D deficiency who have had one episode of demyelination would benefit from vitamin D supplements.

This study does not tell us whether vitamin D supplements can prevent MS from developing before any symptoms occur, or in people who may be at higher risk for MS because of a family history of the disease.

Further research is now underway to understand more about the effects of vitamin D on the immune system and the brain and spinal cord in this group.

More work is needed to uncover the mechanisms underpinning the role of latitude and sunshine in the risk of developing MS.

What does this mean for people with MS?

Having sufficient vitamin D is important for immune system function, bone health, and other bodily systems.

Individuals who have questions about whether they have a vitamin D deficiency and whether they should consider taking supplements should consult their MS healthcare provider.

Along with the results of this study, further studies of vitamin D supplementation underway internationally will help develop recommendations about the use of vitamin D supplements by people living with MS.

The importance of clinical trials in MS

Professor Taylor said, “On behalf of the entire study team, we wish to thank all the study participants and investigators for their participation and dedication over so many years.

Dr Morahan said, “We are very proud to have funded and facilitated this world first clinical trial, and so grateful to the participants who took part in the trial and the wider Australian MS community for supporting us to address this important question for people living with MS.


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MS development not prevented by vitamin D supplements in people at high risk