There is quite a bit of "spin" that is put on the many supplements and vitamins that are available for purchase by the common consumer. Unfortunately, these additives are not regulated very closely, and so what they actually contain may be far different from what they state. Furthermore, there is wide variability of research on all of these, which means that it is unknown if there is any benefit at all to their use.
For the most part, it has been found that a healthy, well rounded diet high in fruits and vegetables is more likely to lead to long term health benefits than any amount of supplement or other vitamin additions. This is because the vitamins and minerals are needed in relatively small amounts, which can usually be obtained best through a regular, healthy diet.
Obviously, many numerous health food stores would have you believe otherwise, and so you will need to decide for yourself which supplements you choose to take. Please discuss any and all of these with your primary care doctor
before starting them, as many of these can interact with your other medications, and may have other side effects as well.