Taking vitamin D supplements or exposure to ultraviolet B rays (UVB) may help prevent pancreatic cancer, a study in The Journal of Steroid Biochemistry and Molecular Biology suggests.
Vitamin D deficiency has been linked to more than 17 types of cancers. The current study led by Dr. Cedric F Garland at University of California in La Jolla, California and colleagues found greater exposure to UVB rays associated with lower incidence of pancreatic cancer.
Early cohort studies have linked high serum 25-hydroxyvitamin D [25(OH)D] to low risk of pancreatic cancer, but not all studies are consistent. It remains largely inconclusive whether vitamin D deficiency could affect the development of pancreatic cancer.
In the current study, Garland et al. analyzed the association between cloud-adjusted UVB irradiance and age-adjusted standardized incidence of pancreatic cancer and found low ultraviolet B irradiance, which means low serum levels of vitamin D, is associated with high incidence of pancreatic cancer.
Specifically, people in countries with low UVB irradiance were 6 times more likely to develop pancreatic cancer than those in countries with high UVB irradiance. The association was significant even after adjustment for other risk factors of pancreatic cancer.
The study concluded the inverse association of cloud-adjusted UVB irradiance with risk of pancreatic cancer is consistent with the inverse association of vitamin D deficiency with risk of pancreatic cancer in countries with low UVB irradiance, which suggests that vitamin D may play a role in the etiology of pancreatic cancer.
UVB is the type of UV ray in sunlight that triggers biosynthesis of vitamin D. UV is a known cancer-causing agent and when a person is overexposed to UV, particularly UVB, he is at higher risk for skin cancer. However, studies suggest although overexposure to the sun is a risk factor for often non-lethal skin cancer, adequate sun exposure helps prevent the development of more aggressive malignancies such as pancreatic cancer.
Cedric F. Garland, Raphael E. Cuomo , , Edward D. Gorham, Kenneth Zeng, Sharif B. Mohr, Cloud cover-adjusted ultraviolet B irradiance and pancreatic cancer incidence in 172 countries, The Journal of Steroid Biochemistry and Molecular Biology, Available online 9 April 2015
