Low vitamin D predicts development of MS in CISers

Low vitamin D levels in MS; cause of consequence, chicken or egg? #MSBlog #MSResearch

Epub: Martinelli et al. Vitamin D levels and risk of multiple sclerosis in patients with clinically isolated syndromes. Mult Scler. 2013 Jul.

BACKROUND: Growing evidence suggests that vitamin D deficiency may be one of the most important environmental factors for the development of MS.

OBJECTIVES: The objectives of this paper are to evaluate serum 25-hydroxyvitamin D (25(OH)D) levels in people with clinically isolated syndromes (CIS) and to examine whether they are related to MS risk.
METHODS: This is a retrospective study of 100 CISers hospitalized from 2000 to 2009 at San Raffaele Hospital, Milan, Italy. They evaluated baseline 25(OH)D level as well as clinical, brain magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) data.

RESULTS: A total of 52% of CISers had vitamin D deficiency (25(OH)D < 50 nmol/l). During follow-up (median: 7.17 years), 55 CISers developed clinically definite MS (CDMS). CISers with very low (< 10th percentile) and low (< 25th percentile) 25(OH)D levels were particularly at risk of CDMS (HRs (95% CIs): 2.12 (0.91-4.96) and 1.61 (0.85-3.03), respectively), while no further reduction in the HRs of disease was observed at high levels of 25(OH)D. This association was even stronger after adjustment for additional risk factors for CDMS development (HRs (95% CIs) for 25(OH)D levels < 10th and 25th percentiles: 3.34 (1.32-8.45) and 2.04 (0.96-4.36), respectively).

CONCLUSION: Low serum vitamin D is associated with increased MS risk in CISers.


"MS risk in this study refers to the second attack or clinically definite MS under the older Poser diagnostic criteria of MS. Most CISers are now classified using the McDonald criteria as having MS after their first attack."

"Chicken or egg? Does low vD levels cause the second attack? If this was the case then vD supplementation to raise the levels of vD to normal would prevent or reduce the chances of a second attack. This strategy is currently being tested in a clinical trial in Australia; unfortunately the UK who were meant to join forces with the Australians in doing this study but our component didn't get funded. This is a great pity as the Australian arm may be under powered. Prof. John Zajicek from Plymouth was the principal investigator on the grant application to the MS Society for the UK component of this study. The other explanation for the low vD levels is that the CISers with the highest likelihood of converting to MS have more active immune systems that consume vD, which lower blood vD levels; i.e. low levels of vD are a consequence not a cause of the conversion to clinically definite MS. If this was the case then supplementing with vD will not prevent or reduce the chances of converting to clinically definitive MS. This is why we need experimental proof, i.e. randomised double-blind controlled trials, to work out if low vD levels in MS the cause of MS or simply associated with active MS."

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