It depends on what you are looking for and in what quantity. A good (really really good) COMPLETE multi vit/min supp will have pretty much everything...meaning A, all the B's, C, D, E, and maybe even K, plus most the minerals (chelated minerals are better). It is okay to take some extra individual supplements in addition to your multi even if your multi contains some of that already, BUT only if you think you need more of that particular vitamin or mineral. It all depends on the quantity you want to get from each vitamin and mineral. If your multi contains what you need, then there is no need to another individual supp. However, this usually isn't the case as no multi contains EXACTLY what we're looking for.