Association Between Vitamin Intake and Colorectal Cancer: Evidence from NHANES Data.

Purpose: This study aims to investigate the associations between vitamins and colorectal cancer (CRC) based on a national sample of US adults.

Methods: A total of 6200 samples were collected from the National Health and Nutrition Examination Survey to explore the relationship between vitamins (specifically, A, C, and D) and CRC. Logistic regression models were employed to assess the associations between dietary vitamin intake and CRC.

Results: Our findings indicate a negative association between vitamin C intake and CRC. However, the associations of vitamin A and vitamin D with CRC were not statistically significant. For vitamin C, compared to the first tertile, the odds ratios (ORs) and 95% confidence intervals (CIs) were 0.91 (0.76-0.97) for the second tertile and 0.81 (0.64-0.95) for the third tertile (P < 0.01). Conversely, for vitamin A, compared to the first tertile, the odds ratios (ORs) and 95% confidence intervals (CIs) were 1.02 (0.82-1.22) for the second tertile and 1.04 (0.75-1.25) for the third tertile (P < 0.01). For vitamin D, compared to the first tertile, the odds ratios (ORs) and 95% confidence intervals (CIs) were 0.96 (0.84-1.06) for the second tertile and 1.01 (0.83-1.15) for the third tertile (P < 0.01). Additionally, the negative association between vitamin C and CRC was more pronounced among females (0.76, 0.67-0.92), individuals aged 60 and above (0.75, 0.69-0.95), and those with a BMI > 30 (0.78, 0.67-0.93).

Conclusion: Our findings suggest that higher vitamin C intake is associated with a reduced prevalence of CRC. However, further large-scale prospective cohort studies are warranted to validate our results.