Which are the positive and/or negative side effects of taking a multivitamin?

Controversial: If you are not pregnant or not old, there doesn't seem to be any benefit of taking a multivitamin if you get enough sun, eat wild salmon and lots of fruits, vegetables, nuts, beans, and seeds. If you are deficient and you can't eat certain foods, they can be beneficial. Take too much and they can be harmful. Avoid pills whenever possible. If you take, the the brand matters.