Association Between Vitamin B12 Intake and Mortality in Patients with Colorectal Cancer: The US National Health and Nutrition Examination Survey, 1999-2018

Vitamin B12 plays a role in DNA methylation, influencing the 1-carbon cycle; However, its effect on colorectal cancer (CRC) mortality remains uncertain. This study assessed the relationship between vitamin B12 intake and all-cause and cancer-specific mortality among CRC patients. We analyzed data from the NHANES from 1999 to 2018, using multivariable Cox regression, competing risk model, Kaplan-Meier survival curves, and stratified analysis with interaction effects. The studied involved 4,554 cancer patients (mean age 65.8 years, 47.6% males). Results from multivariate Cox regression indicated that each additional 1 mcg/day of dietary vitamin B12 independently increased the risk of all-cause (HR, 1.07; 95% CI: 1.04-1.09,