I am astonished by the vitamins, minerals etc we need to take daily. what needs an considerably healty "average" 20 old male do have to get daily?

Eat sensibly: In the studies i've seen of people who eat a reasonable diet (a variety of fruits and vegetables, a good iron source and avoiding the worst of the greasy / sugary / salty stuff), adding vitamin supplements did not improve their health. I bet you already see through the glitzy ads for the pricey "supplements" and if you choose a supplement, it'll be a cheap drugstore-chain vitamin & mineral tablet.