This study from the US looked at the relationship of sun exposure history, supplementation and environmental factors to vitamin D levels in multiple sclerosis patients and evaluated the associations between sun exposure and MRI measures.
264 MS patients underwent neurological and 3 T MRI examinations as well as blood tests to measure vitamin D metabolites using mass spectroscopy. Results showed that vitamin D supplementation, BMI, summer sun exposure and darker eye colour had the strongest associations with vitamin D metabolite levels in the MS group.
Interestingly, summer sun exposure was associated with increased grey matter volume (GMV) and whole brain volume (WBV) after correcting for EDSS in the MS group. Inclusion of 25-hydroxy vitamin D3 levels did not substantially affect the positive associations of sun exposure with WBV and GMV in the MS group. Therefore, sun exposure may have direct effects on MRI measures of neurodegeneration in MS, independent of vitamin D.
Authors: Zivadinov R, Treu CN, Weinstock-Guttman B
Source: J NeurolNeurosurg Psychiatry. 2013 Feb 5. [Epub ahead of print]
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