I realize that a personal testament is anecdotal, but about 10 years ago I stopped taking vitamins and instead just focused on a balanced diet. I feel better and it costs less. There are legitimate reasons for some people to take vitamins, but if you can do it with a better diet, I think you are better off. If you are taking vitamins, try not taking them and instead work on your diet and see what you think. I think somethings are difficult to prove scientifically and instead you have to do what works for you.