A team from the University Hospital of Essen, Germany, examined the relationship between the risk of colorectal adenoma and serum concentrations of vitamins A, C, E, and carotene.
The population-based case-control study enrolled 105 cases of colorectal adenoma and a similar number of hospital controls showing no polyps at colonoscopy. In addition, a second control group of population controls were investigated.
|Serum vitamin A concentrations were inversely related to risk of colorectal adenoma.|
There were found to be no significant associations with serum concentrations of vitamins C and E and carotene.
On the other hand, serum concentrations of vitamin A were significantly inversely related to the risk of colorectal adenoma when cases were compared with both control groups.
After adjustment for energy intake, smoking, alcohol, estrogen therapy, body-mass-index, and social class, the researchers found the inverse association between vitamin A and colorectal adenoma to be even more marked.
For the highest versus the lowest quartile of serum levels, the adjusted relative risk was 0.23 in relation to hospital controls and 0.08 in relation to population controls.
Researcher B. Breuer-Katschinski concluded on behalf of the team, "These findings suggest that the risk of developing colorectal adenomas is reduced in those with high vitamin A levels."