A study published in the British Medical Journal suggests that people born in the summer months have a higher risk of developing multiple sclerosis.
The study was based on the records of 1,524 people with MS born in Australia between 1920 and 1950. Researchers obtained data on month and region of birth for each individual and accounted for regional and seasonal variations when calculating their levels of exposure to ultraviolet radiation at birth.
Findings from the study showed that there was a much higher number of people born in the Australian summer months of November and December compared to those born in the Australian early winter months of May and June.Interestingly, the researchers found that it was the level of exposure to sunlight during the first trimester (first three months) as opposed to the entire pregnancy duration that was responsible for modifying the risk of developing MS in offspring. The authors of the study hypothesise that concentrations of vitamin D might be particularly important in the development of the central nervous system during the first three months of embryonic development.
Pam Macfarlane, Chief Executive of the MS Trust said, "The findings of this study are very interesting - particularly when viewed alongside the results of a Scottish study which also indicated that month of birth influenced the risk of developing MS. Both studies add to our understanding of the link between vitamin D and MS."
