I thought it was bs when I first read it as well, that is why God (or some guy claiming to be God), created Google, to verify things like this. Type "Codex, Vitamins" into a search engine and you will literally get hundreds of sources that all say the same thing.
From what I understood from the articles, they aren't bills being passed in Congress, but rather a proposal put forward by the WTO, which the USA is apart of and will be bound to if passed. It doesn't look like bs to me, but what does sound like bs to me is that in the end of those articles they all say "you can do something about this", clearly Congress cannot stop the WTO from passing such a proposal besides using the ten measly votes that this country holds to vote against it (which would not be enough anyways).
I personally do not think that this will pass, but then again I did not think that Bush will still be President in 2005. If this does pass, I don't think he will say "**** that ****", like he does with the UN. He is in the drug companys' pockets which means that he can only profit from this.