['Multivitamin use is widespread in the United States, especially among patients with cancer. However, the influence of multivitamin supplementation on cancer recurrence and death after a curative resection of colon cancer is unknown.', 'We conducted a prospective, observational study of 1,038 patients with stage III colon cancer enrolled in a randomized adjuvant chemotherapy trial. Patients reported on multivitamin use during and 6 months after adjuvant chemotherapy. Patients were observed until March 2009 for disease recurrence and death. To minimize bias by occult recurrence, we excluded patients who recurred or died within 90 days of their multivitamin assessment.', 'Among 1,038 patients, 518 (49.9%) reported multivitamin use during adjuvant chemotherapy. Compared with nonusers, the multivariate hazard ratio (HR) for disease-free survival was 0.94 (95% CI, 0.77 to 1.15) for patients who used multivitamins. Similarly, multivitamin use during adjuvant chemotherapy was not significantly associated with recurrence-free survival (multivariate HR, 0.93; 95% CI, 0.75 to 1.15) or overall survival (multivariate HR 0.92; 95% CI, 0.74 to 1.16). Multivitamin use reported 6 months after completion of adjuvant chemotherapy was also not associated with improved patient outcome, and consistent use both during and following adjuvant therapy conferred no benefit. Neither an increasing number of tablets nor increasing duration of use before cancer diagnosis was associated with cancer recurrence or mortality. Multivitamin use also did not improve the rates of grade 3 and higher GI toxicity.'] Is multivitamin use associated with cancer recurrence or survival in patients with stage III colon cancer : findings from CALGB 89803?