Aberdeen Scientists Find Link Between Light Deficiency and Multiple Sclerosis

Aberdeen scientists have found that artificial sunlight can have a “striking effect” in helping treat sufferers of diseases such as multiple sclerosis.

Researchers from Aberdeen University studied patients in the north of Scotland – which has the highest rate of MS in the UK - who were being treated during winter with artificial UV (ultraviolet)-B light therapy for skin diseases caused by their immune systems acting inappropriately.

The research - published in the Journal of Allergy and Clinical Immunology – shows how UV-B light boosts vitamin D, as well as cells in our body that are responsible for regulating or balancing the immune system. Vitamin D is made in our bodies by UV-B light from the sun.

Some studies have suggested a link between vitamin D deficiency and autoimmune diseases such as MS.

This possible link might also explain the increasing prevalence of autoimmune disease among those living far from the equator, where there are lower levels of winter sun.

Autoimmune diseases - like MS and type 1 diabetes - are diseases where the immune system mistakenly attacks the body’s own tissues or harmless substances that enter the body.

Dr Anthony Ormerod, clinical reader in dermatology at the university, said: “Our study shows that UV-B light, which mimics sunshine, can have a striking effect on the immune system of patients.

“We found that UV-B light boosted the production of vitamin D, and of regulatory T cells, which play an important role keeping our immune systems in check.

“Our findings have important implications for future interventions including the recommendations for healthy lifestyle and a possible role for phototherapy and/or vitamin D supplementation in the prevention or treatment of autoimmune and inflammatory diseases.

“While too much exposure to sunlight is harmful and increases skin cancer risk, these results suggest that subjects in our study would have some benefits from small amounts equivalent to summer exposure in the winter but more work needs to determine the role of sunlight and the role of supplementing the diet with vitamin D.”

Dr Helen Macdonald, senior lecturer in nutrition and translational musculoskeletal research at the university and chair of the National Osteoporosis Society Nutrition and Lifestyle forum, said: “There are risks associated with high levels of both therapies, so it is important that we get the balance right.

“We would also want to stress that we are not advocating sun bed use since this is not the same type of radiation produced by sun beds which already have well-documented health risks.

“The average dose of UV light that the volunteers received was the equivalent to sunlight exposure in Aberdeen over spring and summer and further work is required to determine if lower doses are effective.”

Professor Mark Vickers, chair in applied medicine at the university, added: “Ours is the first study to demonstrate in patients a cause and effect between UV light, vitamin D and systemic immune function in people.”

Vitamin D deficiency confirmed as common across a range of rheumatic conditions

Vitamin D deficiency confirmed as common across a range of rheumatic conditions

Two separate studies have shown that vitamin D deficiency is common in patients with a range of rheumatic diseases, with over half of all patients having below the ‘normal’ healthy levels of vitamin D (48-145 nmol/L) in their bodies.

A further study assessing response to vitamin D supplementation found that taking the recommended daily dose did not normalise vitamin D levels in rheumatic disease patients. The results of these three studies were presented today at EULAR 2010, the Annual Congress of the European League Against Rheumatism in Rome, Italy.

A UK study of 180 patients aimed to assess mean levels of vitamin D in patients with inflammatory joint diseases, osteoarthritis and myalgia (muscle pain that, when experienced long term may be associated with nutritional deficiency).

Data on vitamin D levels were gathered and results showed that 58% of individuals with a rheumatic condition had levels below that clinically considered to be ’sufficient’ in healthy subjects (48-145 nmol/L).

An Italian study of 1,191 RA patients aimed to determine a correlation between vitamin D deficiency and several different clinical measures of disease activity.

Researchers found that, regardless of supplementation, levels of 25-hydroxyvitamin D (25(OH)D), (a standard clinical measure of vitamin D in the blood), were lower than healthy levels (<50 nmol/L) in 85% of the patients not taking a vitamin D supplement and in 60% of those taking 800 IU or more vitamin D daily as a supplement.

In non-supplemented patients levels of 25(OH)D significantly correlated with three measures of disease activity – the Health Assessment Questionnaire Disability Index, (p=0.000) the Mobility Activities of Daily Living Score (p=0.000) and the Number of Swollen Joints count (p=0.000).

“We have seen in studies that vitamin D deficiency is common in patients with a range of rheumatic diseases, and our results have confirmed this using several clinically accepted measures of disease activity,” said Dr. L. Idolazzi, of the Rheumatology Unit, University of Verona, Italy.

“What we need to see now is a range of long term studies, which examine the clinical response of patients to vitamin D supplementation.”

Furthermore, a third study undertaken in Italy aimed to evaluate the affect of vitamin D supplementation in patients with inflammatory autoimmune disease (IAD) and non-inflammatory autoimmune disease (NIAD).

Following supplementation, only 29% patients reached vitamin D levels greater than the level clinically considered to be ’sufficient’ in healthy subjects, with no significant differences in vitamin D levels observed between the IAD and NIAD groups.

“Whilst it is well known that hypovitaminosis D is often seen in patients with inflammatory autoimmune diseases, the effects of supplementation have not been fully investigated in this setting,” said Dr. Pier Paolo Sainaghi of the Immuno-Rheumatology Clinic, A. Avogadro University of Eastern Piedmont, Novara, Italy and author of the third study.

“The results of our study show that daily 800-1,000 IU supplementation is not sufficient to normalise vitamin D levels in patients with rheumatologic or bone conditions. What is unclear is whether a higher dose would be more effective.”