The relationship of vitamin D status, smoking, and colorectal adenoma: a retrospective study in an ethnically diverse community

Abstract

Objective: Circulating 25-hydroxyvitamin D (25OHD) level is suggested to be negatively correlated with risk of colorectal cancer (CRC) and colorectal adenoma (CRA), but most of the epidemiological data were originated amongst Caucasians and African Americans. This study aimed to investigate the relationship between vitamin D status, smoking and CRA in an ethnically diverse community with a high Hispanic density.

Methods: In this retrospective study, we included 233 patients who underwent complete colonoscopies from 2009 to 2011, and their serum 25OHD levels in the winter season had been measured. Among them, 65 adenoma cases and 168 adenoma-free controls were identified and evaluated for the association of CRA with smoking, ethnicity and serum 25OHD level using unstratified and stratified multivariate logistic regression analyses.

Results: In our study participants, the mean serum 25OHD level and the percentage of Hispanics were lower in the adenoma group versus the control group, while no black-white difference was noted in the CRA prevalence. When adjusted for 25OHD level, the lower rate of adenoma in Hispanics compared to non-Hispanics was attenuated and became statistically insignificant. A mild protective effect of vitamin D (6% reduction) on the CRA risk was found significant for active smokers, but not for non-smokers. A detrimental impact of smoking in the CRA risk was only shown among non-Hispanic patients, but not among Hispanics irrespective of vitamin D status.

Conclusions: Our data suggest a marked distinction between Hispanics and non-Hispanics in the risk of CRA. The reduced adenoma prevalence among Hispanics vs. non-Hispanics could be partially explained by vitamin D status, cigarette smoking and their interactions. Future larger-sized multi-center studies on vitamin D status and ethnicity, as well as dietary, behavioral, genetic factors and their interactions for CRA and CRC are needed. This article is part of a Special Issue entitled 'Vitamin D Workshop'.