I agree totally with Tampa Terry. You may not feel a big difference between multi vitamins. It's not like taking a performance enhancing nutrient like Tribex, or a good Creatine powder. However, over the long haul you will see a big difference.
I began training in my late teens. thirty years later, all of the guys that I trained with in the earlier years have either given it up because of health concerns, or can't continue for some other reason due to the age factor. I am still setting personal records and feel great. I have also always purchsed the best supplements, including the best multi vitamin available!
Naturally there is no scientific way to track my training longevity directly to my purchase of a good quality multi vitamin. On the other hand none of my early training partners believed in quality vitamin supplementation and they look, act and if you ask them, they will tell you they feel their age, or older.
I have stated this before on this board, and will many more times I am sure. You have just one body. You will either take care of that body as best you can, or you won't! I have seen some trainees who will not take any sort of vitamin or supplement for longevity, or purchase the cheapest supplements available. Yet, they buy the finest oil and gas for their car. They may not drive that car more than a few years. You are stuck with the body you have now forever!
Still other people purchase the best cloths, hair and skin care products (usually women, sorry Terry). Yet, when it comes to their health they think lifting a couple times per week and doing some cardio is going to keep them in the game. If I didn't care so much it would be funny to watch.
Face this relaity: Someday if you are lucky, you will eventually be thirty years of age, then forty, then fifty, sixty and so on. I know you think you are naturally going to feel the way you do now. I have news for you, if you don't do something to ensure this occurrence, it is not going to happen!
Okay, I went on a bit long. I only do so because I care. Now get your butt out there and do what your Aunt Terry and Uncle Zeb tell you! Do the research, and purchase a quality vitamin product! You young whipper snapper. Haha.