(P13-042-23) Dietary Intake of Vitamins and Risk of Cancer Mortality Results From the Golestan Cohort Study

Objectives: The associations between vitamin deficiency and gastrointestinal (GI) cancer mortality are not fully understood. This study evaluated the association between vitamin intakes including vitamins A, B, C, K, and β-carotene and GI cancers mortality in a prospective study in a Middle Eastern population.

Methods: We used data from the Golestan Cohort Study, which has followed participants aged 40-75 years since 2004. We excluded subjects reporting extreme intakes of total energy and a positive history of cancer, CVD, or diabetes at baseline. Vitamin intake was estimated from the baseline food frequency questionnaire. Supplement use was not common in this population. We used Cox proportional hazards models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for mortality using the lowest quintile of intake as a reference group for each vitamin with adjustment for potential confounders. We also assessed linear associations per half of an interquartile range as a unit.

Results: We analyzed 42,456 subjects that had a mean age of 51.56+8.79 years at baseline. During 579,339 person-years of follow-up (median: 14.1 Years), 945 (2.22%) GI cancer deaths were recorded. We observed a significant inverse association between vitamin A (HR _{Q5 vs Q1}=0.73, 95% CI=0.59-0.92), β-carotene (HR _{Q5 vs Q1}=0.75, 95% CI=0.59-0.96) with total GI cancers (P_trend < 0.05). β-carotene also associated inversely with esophageal cancer mortality (HR _{Q5 vs Q1}=0.69, 95% CI=0.43-1.11, P<sub>trend < 0.05). Also, a significant inverse association between riboflavin (HR _{Q5 vs Q1}=0.31, 95% CI=0.11-0.85) and pancreatic cancer mortality were observed (P_trend < 0.05) in the fully adjusted model. Other vitamins such as vitamin C, K, and other B vitamins did not indicate a significant association with GI cancer mortality. Moreover, the HRs of cancer mortality per one-unit increase in vitamin intake were not significant.

Conclusions: These findings suggest that dietary intake of β-carotene and vitamin A were inversely associated with GI cancer mortality. Moreover, β-carotene and riboflavin intake showed a significant inverse association with esophageal and pancreatic cancer mortality, respectively. Further confirmation in larger studies and in meta-analyzes is needed.

Funding Sources: Tehran University of Medical Sciences