A new study published by the University of California in the PLOS one journal has revealed vitamin D exposure is linked to an increased risk of developing leukemia. The American Cancer Society estimates that there are 54,270 cases and 24,450 deaths from leukemia in the U.S each year.
The findings are linked to latitude with lower sunlight/ultraviolet B (UVB) exposure and vitamin D deficiency. Vitamin D is produced when sunlight hits the skin and triggers synthesis.
The UC study investigated rates of leukemia in 172 countries, with age related data obtained from GLOBOCAN, an international agency for research on cancer that is part of the World Health Organization. The information was obtained from the International Satellite Cloud Climatology Project.
“These results suggest that much of the burden of leukemia worldwide is due to the epidemic of vitamin D deficiency we are experiencing in winter in populations distant from the equator,” said Cedric Garland, DrPH, adjunct professor in the Department of Family Medicine and Public Health and member of Moores Cancer Center at UC San Diego Health.
“People who live in areas with low solar ultraviolet B exposure tend to have low levels of vitamin D metabolites in their blood,” Garland said. “These low levels place them at high risk of certain cancers, including leukemia.”
Prior studies have specified that cancers, including breast, colon, pancreas, bladder and multiple myeloma are linked to reduced UVB radiation exposure and lower vitamin D levels.
Leukemia rates were lowest in equatorial countries such as Bolivia, Samoa, Madagascar and Nigeria. They are highest in countries relatively closer to the poles, such as Australia, New Zealand, Chile, Ireland, Canada and the United States.
“These studies do not necessarily provide final evidence,” said Garland, “but they have been helpful in the past in identifying associations that have helped minimize cancer risk.”
Low cloud cover-adjusted ultraviolet B irradiance is associated with high incidence rates of leukemia: Study of 172 Countries, Cedric Garland et al., PLOS One, doi: 10.1371/journal.pone.0144308, published online 4 December 2015.