All of the essential vitamins can be taken at the same time. In fact, that's the best way to get them since most work synergistically. There are a few minerals, in some clinical individual cases, which are often better absorbed without any competition from vitamins, but this is rare and only a qualified health professional can make that decision for you after a specific deficiency diagnosis. For everyone else, the best way to get all the vitamins you need daily is to eat the best you can (follow a plan similar to our menus in the dotFIT program) and take a daily multivitamin and mineral formula.