OBJECTIVES: Month of birth has been associated with the environmental factors for multiple sclerosis (MS). This study aimed to investigate whether individuals with MS had significantly different frequencies of birth in a particular month of the year
METHODS: In this study, performed as a part of the fourth Japanese nationwide survey of MS (n=906). The number of births in every month was counted. Control data were obtained from birth records of the Japanese general population of the median years of birth of each group. Differences in the month-of-birth distributions between the patients and the general population were assessed.
RESULTS: In MS patients significantly more patients were born in January and June, whereas significantly fewer patients were born in May, compared to the general population. The seasonal patterns of birth were not in association with those of ambient ultraviolet (UV) radiation.
CONCLUSIONS: A different distribution of month of birth in Japanese MS patients from the general population suggests some role for environmental factors in the pathogenesis. Environmental factors other than UV radiation should be further elucidated in Japanese and other Asian MS cohorts.
Prof G and Ram have been building up a picture of Vitamin D exposure and the risk of MS.
The month of Birth supports this view, but there have been some differences.
Brazil is on the equator (or slightly south) and so should get more constant sunlight and there is the same month of Birth as Northern Europeans and here we have a Northern Hemisphere country with a different month of Birth effect with higher births in January and June and lower in May compared to high in November and low in April in Northern Europeans
Japan is further South than UK.
Do you have any ideas that can bring this into the Worldview of MS?