Study Links Low Vitamin D Levels to Greater Bladder Cancer Risk

Research presented at the Society for Endocrinology Conference, held November 7-9 in Brighton, UK, found a connection between low levels of vitamin D and higher risk of bladder cancer.

Investigators from the University of Warwick in Coventry, UK, performed a systematic review of 7 studies, with the goal of evaluating the link between vitamin D and bladder cancer. The number of participants in each of these studies ranged from 112 to 1125, according to the authors, who point out that some of the studies measured vitamin D levels before diagnosis, while others measured vitamin D levels during diagnosis, and others did so at the follow-up stage.

Ultimately, 5 of the 7 studies the authors reviewed determined that the risk of bladder cancer increases when vitamin D levels are low. In addition, the researchers saw a correlation between higher vitamin D levels and better survival and outcomes in individuals with bladder cancer.

The investigators also examined transitional epithelial cells, which line the bladder, and found that these cells can activate and respond to vitamin D. According to the authors, these cells can also synthesize enough vitamin D to activate a local immune response. In turn, the immune system could use this information to prevent cancer by recognizing abnormal cells before they have a chance to further develop.

While noting that additional clinical studies are needed in order to test this association, the researchers concluded that a correlation exists between bladder cancer risk and low vitamin D levels. If this link is confirmed, the authors say, administering supplementary vitamin D could be a safe and cost-efficient way to prevent bladder cancer.  

"Vitamin D insufficiency and deficiency is widespread throughout the world," said Rosemary Bland, PhD, an associate professor at the University of Warwick, and lead author of the study.

"It is known that vitamin D is required for healthy bones, and recent evidence has highlighted that it may have an important role in the immune system," said Dr Bland, adding that the results from this study may be applicable to other cancers. 

Therefore, the message for primary care practitioners is that "they should aim to ensure that their patients have sufficient levels of vitamin D," she said.

"This would usually be achieved by taking a vitamin D supplement. Recommendations as to the serum vitamin D levels that are adequate and the supplemental regime used to achieve these are guided by relevant health care providers."

—Mark McGraw

Bland R, Chivu C, Jefferson K, MacDonald D, Iqbal G, Dunn J. Low vitamin D is associated with increased bladder cancer risk; a systematic review and evidence of a potential mechanism. Presented at: Society for Endocrinology Annual Meeting; November 7, 2016; Brighton, UK. Abstract P129.