If you need a reminder to take your vitamin D today, here’s a good one. Researchers at the University of California, San Diego School of Medicine report that people who live at higher latitudes, with lower sunlight/ultraviolet B (UVB) exposure and greater prevalence of vitamin D deficiency, are at least two times at greater risk of developing leukemia than people who live near the equator.
“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.”
According to the American Cancer Society, 54,270 cases and 24,450 deaths from leukemia occur in the United States alone each year.
Garland and colleagues have studied other cancers and their relation to vitamin D, including breast, colon, pancreas, bladder and multiple myeloma. In each study, they found that reduced UVB radiation exposure and lower vitamin D levels were associated with higher risks of cancer.
Leukemia rates were highest in countries relatively closer to the poles, such as Australia, New Zealand, Chile, Ireland, Canada and the United States. They were lowest in countries closer to the equator, such as Bolivia, Samoa, Madagascar and Nigeria.
“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.”