I can't think of a reason that an IBSers would need different/more vitamins than anyone else.However, if you find a pretty limited diet controls your symptoms it may be worth looking at the diet (like run it through a program to get the nutritional info) and see if there is something you are missing that you absolutely should be taking. For instance people who avoid dairy may not get enough calcium and would want to supplement.Now there are somethings that may be helpful, but not because it is IBS but more general stuff.Like people who are lacking energy might want to take a B-complex as well as vitamin D and selenium because that set of vitamins seems to help people who are running a bit low feel better.K.