A review of 67 studies involving 230000+ people found that the vitamin supplements mayn't cut risk of dying. Even more, some supplements may increase mortality.
The study examines effect of Vitamin A, Vitamin C, Vitamin E and selenium intake with varying doses.

The study found that Vitamin A, Vitamin E and beta-carotene increases death risk. Vitamin C and selenium seem to not affect death risk.
Also Vitamin C is reported to not increase longevity.

Six-year vitamin E supplementation increased tuberculosis risk by 72% in male smokers who had high dietary vitamin C intake, but vitamin E had no effect on those who had low dietary vitamin C intake, according to a study published in the British Journal of Nutrition.

(Source: http://www.sciencedaily.com/releases/2008/02/080221101425.htm)

Vitamin E and ?-carotene affect the immune function and might influence the predisposition of man to infections.