Vitamin supplement use and risk for oral and esophageal cancer.

In a hospital-based case-control study, 290 oral cancer cases and 133 esophageal cancer cases were queried as to smoking status, alcohol consumption, and dietary exposures, including vitamin supplement history. Among oral cancer cases, vitamin E use appeared to exert a protective effect. Vitamins C and E had protective effects among esophageal cancer cases. When stratified by smoking status, the protective effect of vitamin C use in esophageal cancer was significant only among current smokers, as was vitamin B use. A reduced risk of oral cancer was correlated with multivitamin use and increasing vegetable consumption, as was vegetable/fruit consumption and vitamin C supplementation. Among esophageal cancer cases, increasing meat consumption and vitamin C use were associated with a significantly reduced cancer risk.