Although many generous Canadians already donate blood regularly, the more donors there are, the better. But why is blood demand so high? Author: Alison MacPhee Blood: Background Information Approximately 50% of Canadians will either be in need of blood components or know someone who will at some point in their lives. However, only 4% of Canadians are registered blood donors [1]. These statistics prove just how great the need is for eligible donors to come forward and contribu