It's unclear whether taking vitamin supplements would actually help. (See also the Quantified Health Prize post army1987 linked.)

Regarding medication, I'll add that for people over 40, aspirin seems to be a decent all-purpose death reducer. The effect's on the order of a 10% reduction in death rate after taking 75mg of aspirin daily for 5-10 years. (Don't try to take more to enhance the effect, as it doesn't seem to work. And you have to take it daily; only taking it on alternating days appears to kill the effect too.)