Vitamin A intake was assessed from dietary histories on 452 men with prostate cancer and 899 population controls in Hawaii during the period 1977–1983. In the group of men <70 years of age, there were no significant associations of this nutrient with risk for prostate cancer. In the men ≥70 years, however, risk increased directly with the amount of vitamin A consumed (relative risk of 2.0 for the highest relative to the lowest intake quartile, and a significant linear trend, P < 0.01). The findings were similar for the various components of vitamin A but were somewhat stronger for total carotenes than for total retinol. These results were generally consistent across the five ethnic groups and were not affected by statistical adjustment for dietary fat. Possible mechanisms for this risk enhancement by vitamin A in elderly men are proposed.
Supported in part by Contract 1 N01 CN 55424 and Grants 1 N01 CA 15655 and 1 R26 CA 28943 from the National Cancer Institute. Department of Health and Human Services.