The results of two large, long-term surveys show that adults who got 300 IU to 449 IU (international units) per day had a 43% lower risk of pancreatic cancer. The recommended intake of vitamin D for adults aged 51-70 is 400 IU per day.
Researchers say the findings suggest that vitamin D, which is created in the skin upon exposure to ultraviolet sunlight, and found in fortified dairy products and other food sources, may play an important role in preventing pancreatic cancer. The cancer is the fourth leading cause of cancer death in the U.S.
"Because there is no effective screening for pancreatic cancer, identifying controllable risk factors for the disease is essential for developing strategies that can prevent cancer," researcher Halcyon Skinner, PhD, of the department of preventive medicine at Northwestern University in Chicago, says in a news release.
"Vitamin D has shown strong potential for preventing and treating prostate cancer, and areas with greater sunlight exposure have lower incidence and mortality for prostate, breast, and colon cancers, leading us to investigate a role for vitamin D in pancreatic cancer risk," says Skinner.
"Few studies have examined this association, and we did observe a reduced risk for pancreatic cancer with higher intake of vitamin D," he says.
Vitamin D May Fight Pancreatic Cancer
In the study, researchers analyzed data on vitamin D intake and pancreatic cancer risk among the more than 120,000 men (aged 40 to 75) and women (38 to 65) who participated in the Health Professionals Follow-Up and Nurses' Health studies.
Between the two surveys, 365 cases of pancreatic cancer were reported.
The Northwestern study showed people who consumed in the range of 300 IU to 449 IU per day of vitamin D daily had a 43% lower risk of pancreatic cancer than those with less than 150 IU per day.
Getting more than the daily RDA (600 IU per day or greater) had 41% lower risk than those who consumed less than 150 IU per day.
Even participants who consumed only 150 IU to 299 IU per day had a 22% lower risk than those with less than 150 IU per day.
The analysis took into account factors such as smoking history, multivitamin use, age, and body mass index (BMI).
"In concert with laboratory results suggesting antitumor effects of vitamin D, our results point to a possible role for vitamin D in the prevention and possible reduction in mortality of pancreatic cancer.
"Since no other environmental or dietary factor showed this risk relationship, more study of vitamin D's role is warranted," says Skinner.