Leukemia is a cancer of the blood cells. The exact cause is not known although genetic and environmental factors play a role.


To assess whether there is a relation between leukemia and vitamin D levels.


  1. Individuals living in countries away from the equator, such as the US, Australia, New Zealand, Canada and Ireland, were (at least) twice as likely to have leukemia compared to people living closer to the equator, such as Nigeria, Bolivia, Samoa and Madagascar.
  2. The association was adjusted for sex-specific life expectancy and altitude, according to the authors
  3. The researchers said that  individuals who live farther away from the equator are exposed to less sun, which then creates less vitamin D in the body.

“Importantly, these results suggest that increased levels of UVB irradiance and vitamin D may help prevent development of leukemia.”