A study published online in the journal PLOS One reports that people residing at higher latitudes with lower exposure to sunlight are at greater risk of developing cancer, including leukaemia, a type of blood cancer. The research was undertaken by researchers from GLOBOCAN, a subsidiary of World Health Organization.
The study was published after tracking the frequency of leukaemia cases in 172 countries wherein people living in higher latitudes are at least two times prone to developing leukaemia than those living near the equatorial regions. The study establishes the fact that a majority of leukaemia cases around the world is due to the deficiency of Vitamin D during winter, in populations away from the equator.
Leukaemia cases were the highest in countries such as Australia, New Zealand, Chile, Ireland, Canada and United States, all of which are closer to the poles and were the lowest in countries such as Bolivia, Samoa, Madagascar and Nigeria, which are closer to the equator. Vitamin D is produced when ultraviolet radiation from the sunlight strikes the skin and triggers synthesis.