Is artificial blood safe for vampires to eat?

What are the daily recommended nutritional requirements for a vampire? What does artificial blood taste like? Would you rather be a vampire or a zombie? These are not questions I ever thought I would be asked as a young scientist, but both have featured when I have been communicating my science to the general public. When I was growing up, vampires were evil and to be feared. Yet in recent years it appears that they were, in fact, much maligned and misunderstood; they really just want to live their lives in peace with their mortal compatriots. It is not reported what the late – and recently much lamented – Sir Christopher Lee thought of this transformation, although I strongly suspect that, like myself, he prefers his vampires raw in tooth and claw (or rather fang).