In this retrospective study from Italy the researchers looked at serum 25-hydroxyvitamin D (25(OH)D) levels in people with clinically isolated syndrome (CIS) and the associated risk of MS. They evaluated baseline 25(OH)D, in addition to clinical, brain MRI and CSF data in 100 people with CIS over a nine-year period.
Results showed that 52% had vitamin D deficiency (25(OH)D<50nmol/l). Fifty-five people developed clinically definite MS (CDMS) during follow-up. People with very low (<10th percentile) and low (<25th percentile) 25(OH)D levels were particularly at risk of CDMS. The results remained essentially unchanged after controlling for other confounding factors or known predictors of CDMS.
Interestingly, the researchers found that women with vitamin D deficiency are at a greater risk of developing CDMS than men with comparable deficiency. It is not known why this is the case but one hypothesis is the synergistic interactions between the oestrogen and vitamin D signalling pathway. In the future, they recommend that further multicentre studies with a large number of people with CIS take into consideration all the possible vitamin D confounding factors as well as regions with different sun exposure.
Authors: Martinelli V, Dalla Costa G
Source: Mult Scler. 2013 Jul 8. [Epub ahead of print]
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