August 25, 2015

expert reaction to new study on vitamin D deficiency and MS

A possible link between vitamin D levels and risk of multiple sclerosis (MS) has been explored in a paper published in the journal PLOS Medicine, in which the authors report that gene variants which were associated with lower levels of vitamin D were associated with an increased risk for MS.

Dr Benjamin Jacobs, Consultant Paediatrician and Director of Children’s Service at the Royal National Orthopaedic Hospital, said:

“This study reveals important new evidence of a link between Vitamin D Deficiency and Multiple sclerosis (MS). Data from two massive genetic studies were combined: The European study of 34,000 people’s genes associated with Vitamin D Deficiency (the SUNLIGHT study); and the IMSGC Immunochip study, the largest international genetic study of MS, involving 14,498 MS cases and 24,091 healthy controls.

“The results show that if a baby is born with genes associated with Vitamin D Deficiency they are twice as likely as other babies to develop MS as an adult. This could be because Vitamin D deficiency causes MS or possibly because there are other complex genetic interactions.

We do not yet know if giving healthy children and adults Vitamin D will decrease their risk of developing MS, but clinical trials are being conducted now to study this.”

Prof. Danny Altmann, Professor of Immunology at Imperial College London, said:

“While MS has been understood for several decades to be a neuroinflammatory disease with a cocktail of contributory causes both from genes and the environment (‘nature and nurture’), we have tended to acquire more and more data without perhaps crystallising a clear notion of what this means about the origin of disease or how to prevent it.

“The ‘environmental’ component of susceptibility certainly encompasses many factors, however, considerable attention has focused on individual differences in exposure to sunlight and thus, levels of vitamin D. This vitamin is vital to many biochemical pathways in the body, notably including diverse aspects of efficient function of immunity. It has long been appreciated that there is a geographical correlation between living at latitudes with reduced sunlight and susceptibility to MS.

“What this keynote study by Richards and colleagues offers is an elegant utilisation of data from very large human cohorts to show that there are parts of the human genome that predispose to high or low levels of vitamin D in the blood, this is in turn being related to risk of developing MS.  Until now many of the biggest hits from MS genetic studies have implicated genes controlling immunity, but this study draws our attention specifically to the relationship between exposure to sunlight, immune function and MS risk. This places MS alongside other diseases of immune susceptibility, including many infectious diseases, where risk is associated with low levels of serum vitamin D.

“In many of the other examples tried, the notion that all will be well if we simply give patients a large dose of vitamin D supplements has proved too simple. However, vitamin D is relatively cheap, safe and many of us would be all the healthier if we could achieve the serum levels that our ancient ancestors presumably acquired when roaming outdoors in temperate climates, unclothed and eating a diverse diet including oily fish. While it may be too much to expect therapeutic vitamin D to treat or reverse ongoing MS, this paper will add to the weight of argument for routine vitamin D supplementation of foodstuffs as a broad, preventative, public health measure.”

‘Vitamin D and Risk of Multiple Sclerosis: A Mendelian Randomization Study’ by Lauren E. Mokry et al. published in PLOS Medicine on Monday 24 August 2015. 

Declared interests

None declared