Results of a study led by Dr. Elizabeth Jacobs, professor of epidemiology at the University of Arizona Mel and Enid Zuckerman College of Public Health, support prior data demonstrating that vitamin D plays a key role in bile acid metabolism, and suggest a potential mechanism of action for 25(OH)D in colorectal cancer prevention. The study is published in the journal Cancer Prevention Research.
[Photo: Dr. Elizabeth Jacobs]
While hydrophobic bile acids have been demonstrated to exhibit cytotoxic and carcinogenic effects in the colorectum, ursodeoxycholic acid (UDCA) has been investigated as a potential chemopreventive agent. Vitamin D has been shown to play a role in both bile acid metabolism and in the development of colorectal neoplasia.
Employing a cross-sectional design, the researchers sought to determine whether baseline circulating concentrations of the vitamin D metabolites 25(OH)D and 1,25(OH)2D were associated with baseline fecal bile acid concentrations in a trial of UDCA for the prevention of colorectal adenoma recurrence. They also prospectively evaluated whether vitamin D metabolite concentrations modified the effect of UDCA on adenoma recurrence.
After adjustment for age, sex, BMI, physical activity, and calcium intake, adequate concentrations of 25(OH)D (> 30 ng/ml) were statistically significantly associated with reduced odds for high levels of total (OR=0.61; 95% CI=0.38-0.97), and primary (OR=0.61; 95% CI=0.38-0.96) bile acids, as well as individually with chenodeoxycholic acid (OR=0.39; 95% CI=0.24-0.63) and cholic acid (OR=0.56; 95% CI=0.36-0.90). No significant associations were observed for 1,25(OH)2D and high vs. low fecal bile acid concentrations. In addition, neither 25(OH)D nor 1,25(OH)D modified the effect of UDCA on colorectal adenoma recurrence.
The researchers concluded, this is the first study to demonstrate an inverse relationship between circulating levels of 25(OH)D and primary fecal bile acid concentrations. These results support prior data demonstrating that vitamin D plays a key role in bile acid metabolism, and suggest a potential mechanism of action for 25(OH)D in colorectal cancer prevention.
For More information visit http://cancerpreventionresearch.aacrjournals.org/content/early/2016/04/30/1940-6207.CAPR-16-0033.abstract