In my opinion, it all depends on the doc. I have a friend who alsomt died of a VERY TREATABLE disease as a teenager because her ped KNEW children couldn't get that particular disease. True, she is one of the youngest people on record to need treatment, but the only reason she got it is because she had a family friend who recognized some of the symptoms and insisted her mom DO something...the ped still refused to order ANY tests because she was only 16 and most ppl diagnosed are in their 40's,at least! Luckily my friends mom trusted her friend more than her ped and took my friend somewhere else for a second opinion, now she will be on meds for the rest of her life, but at least she has a life!! The Ped thought he knew more about my friend then anyone else because he had the special training, and kids just don't get that disease!!
On the vitamin side of things, one of my dad's best friends owns a sanitation company-emptying out porta-potties and what not. I have heard from him that they find more barely digested vitamins (some you can even still read the names off of them!) in the potties than any other inorganic matter. To me, that says that they must go right thru you, and exactly how helpful can that be? IMHO, most vitamins are a waste of money, feed your daughter a healthy, well-balanced diet and she will be fine.