[quote=@AdobeFlash]
<Snipped quote by Witch Cat>

when i started thinking about this subject, thats what i thought. e x t r e m e i r o n d e f i c i e n c y
[/quote]

Time to use our favourite tool to ignore problems, Magic! Here's my idea, all blood is infused with magic, Vampires need magic to survive, Vampires evolved to consume blood for magic, and that's why vampires drink blood.