It hasn't. It was just a friendly advice on saving you some money on those vitamin pills. If you are in need of help why question the advice given to you? This is not a place where you can demand answers to all your questions. Your bitch have trouble digesting her food. The vitamins have nothing to do with that. There are things you can give her that helps her digesting. For example appelcider vinegar is supposed to help digestion. I don't know what you are feeding. But when given kibble lots of the natural enzymes in the food has been killed in the process. So if kibble is what you are giving her I suggest you switch her to a more natural and sound raw diet, where there are plenty of enzymes, which is essential for a healthy digestion.
The more info you give us the bigger are the chances that somebody are able to help you out...