People who live in places that receive less sunlight and therefore have lower levels of vitamin D, may be twice as likely to develop leukemia,  a new study finds.

There are about 54,270 cases and 24,450 deaths from leukemia annually in the U.S. There is generally no known way to prevent the disease, which is a type of blood cancer.

Researchers at the University of California, San Diego, analyzed rates of leukemia in 172 countries, then compared that with cloud cover data from the International Satellite Cloud Climatology Project.

Previous studies had found that people living in higher altitudes, and therefore receiving lower sunlight/ultraviolet B exposure, were more likely to be deficient in vitamin D. These studies have found them to be at higher risk for other forms of cancer, including breast, colon, pancreas, bladder and multiple myeloma.

Sunlight is necessary for the body to manufacture vitamin D, which is difficult to obtain in sufficient quantities from food.

The researchers found 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.

While this does not prove that less sunlight and lower levels of vitamin D cause leukemia, such knowledge could prove helpful identifying strategies that could help minimize risk, the researchers said of their study, which appears online in PLOS One.