Taking a high dose of vitamin D can help to regulate the hyperactive immune response in people with multiple sclerosis (MS), a study has found.
American scientists believe their research could point the way towards a simple and cheap treatment for people with the disease, which is caused by the body’s own immune system damaging nerve fibres.
The devastating disease can cause symptoms ranging from mild tingling or numbness to full-blown paralysis.
A growing body of research has found that low levels of vitamin D in the blood are associated with an increased risk of developing the disease, which affects more than 11,000 people in Scotland.
Patients with the disease are also likely to have a greater disability if they lack the vitamin, which is found in sunlight as well as oily fish and eggs.
Experts at John Hopkins University School of Medicine, in Baltimore, studied 40 patients with relapsing-remitting MS, a form of the disorder which has active and passive periods.
The patients received either 10,400 or 800 international units (IU) of vitamin D3 supplements every day for six months.
The first dose was significantly higher than the current recommended daily allowance for vitamin D of 600 IU. Patients taking the high dose experienced a reduction in the percentage of specific immune system T-cells related to MS activity.
Above a certain threshold, every five nanograms per millilitre increase in vitamin D blood levels led to a 1 per cent reduction of the T-cells, the researchers reported in the journal Neurology.
There was no such change seen in patients taking the lower dose.
Lead author Dr Peter Calabresi, professor of neurology at the Johns Hopkins University, said: “These results are exciting, as vitamin D has the potential to be an inexpensive, safe and convenient treatment for people with MS.
“More research is needed to confirm these findings with larger groups of people and to help us understand the mechanisms for these effects, but the results are promising.”
The trial found there were only minor side effects from the vitamin supplements, which did not differ between patients taking the higher and lower doses.
One person in each group had a relapse of disease activity.
The optimal level of vitamin D in the blood for people with MS has still to be determined but would be near the high dose level.
Dr Sorrel Bickley, head of biomedical research at the MS Society said: “The link between vitamin D and multiple sclerosis is a promising area of research. This study, although small, provides new evidence about the safety of high doses of vitamin D and the effect this has on the immune system.
“There are more than 11,000 people in Scotland living with MS and finding treatments that can slow, stop or reverse the worsening of disability is a priority for the MS Society.
“Therefore we look forward to seeing larger and longer term studies to help us understand whether this could be an effective and safe treatment.”