VITAMIN-A, BETA-CAROTENE, AND THE RISK OF CANCER - A PROSPECTIVE-STUDY

Abstract

A cohort of 10,473 residents of Leisure World, Laguana Hills, CA [California, USA], who were initially free of cancer were followed from 1981 to 1986. A health survey questionnaire completed by all cohort members included vegetables, fruits, dairy products, liver, and cereal, as well as specific information on brand and formulation of vitamin supplements containing vitamins A, C, or E. Pathologic diagnosis of incident cancer was confirmed in 643 persons (56 lung, 110 colon, 59 bladder, 93 prostate, 123 female breast, and 202 cancers of other sites). Our study found little indication that increased intake of vitamin A or .beta.-carotene from the diet or supplements protects against the development of cancer overall. Dietary vitamin A intake was highly associated with smoking status; 25% of current smokers were in the highest third of dietary vitamin A consumption versus 32% of past smokers and 36% of never-smokers. In males who never smoked there was some indication that cancer rates decreased with increasing vitamin A intake, but the results were not statistically significant.