ABSTRACT
OBJECTIVES/HYPOTHESIS: With an unacceptably low 5-year survival rate and few identified modifiable factors that affect head and neck cancer (HNC) outcomes, HNC survival remains an important public health problem. Vitamin D has been shown to be associated with immune reactivity and improved outcomes for some cancer sites, but findings are mixed, and few studies have examined vitamin D in relation to HNC. This study aimed to assess the association between vitamin D intake and survival outcomes in HNC patients. STUDY DESIGN: Prospective cohort study. METHODS: This study utilized data on 434 HNC patients with valid pretreatment food frequency questionnaire data who participated in the University of Michigan Head and Neck Specialized Program of Research Excellence epidemiology project. Cox proportional hazard models were used to estimate the associations between total, dietary, and supplemental vitamin D intake and HNC outcomes, while adjusting for other known prognostic factors. RESULTS: After multivariable adjustment, we found a statistically significant inverse trend between total vitamin D intake and recurrence (Q4 vs. Q1 hazard ratio: 0.47, 95% confidence interval: 0.20-1.10, P trend = .048). We observed no association with dietary or supplemental intake separately, and no association was observed with all-cause or HNC-specific mortality. CONCLUSIONS: These findings suggest that HNC patients with lower levels of vitamin D intake are at higher risk of recurrence. If borne out in future studies, our results suggest that increased vitamin D intake through dietary intervention or the use of supplements may be a feasible intervention for prevention of recurrence in HNC patients. LEVEL OF EVIDENCE: 2b. Laryngoscope, E371-E376, 2018.