
Birth month had a significant association with multiple sclerosis (MS), suggesting as much as a 12% swing in risk, probably reflecting ultraviolet (UV) light exposure and maternal vitamin D levels, authors of a meta-analysis concluded.
Data on more than 150,000 patients with MS showed a 5% excess of cases among patients born in April and 5% to 8% reductions in MS risk associated with birth in October or November.
A more conservative analysis showed even greater excess risk in April and May and greater reductions in risk in October and November, as reported online in the Journal of Neurology, Neurosurgery, and Psychiatry.
"This study, which uses the largest number of patients to date, confirms and extends the month of birth effect seen in MS," Ruth Dobson, MRCP, of Queen Mary University of London, and co-authors wrote. "Through the demonstration of an interaction between month of birth effect magnitude and latitude, it supports ambient UV radiation, and hence maternal vitamin D levels, as prenatal environmental modulators of MS risk.
"This finding, which supports concepts hypothesized some years previously, surely adds weight to the argument for early intervention studies to prevent MS through vitamin D supplementation," they added.... Read More - http://www.msrc.co.uk/index.cfm/fuseact ... ageid/1936