The emphasis is not on medical documentation for the support of 
vampirism. Vampirism first exists in the abilities that are present. 
Vampires generally have heightened sensory abilities that other people 
find are absent. These are present in the psychic and empathic 
abilities to percieve and minipulate the mental and emotional energies 
of others who are susceptable to it. It is inherent in the ability to 
percieve this energy around people. Vampirism can be first understood 
in this difference in abilities. As for the attraction of the blood 
energy and the protein and elemental properties of blood, vampires 
have an ability to tap the properties of blood unlike other people. We 
know that blood naturally makes people sick just by it's properties if 
injested too much, and also there can be some addiction to it if it is 
injested over time. 

Vampirism is not a medical disection, it is a mental ability and 
therefore need. vampires thru this awareness and need are natural 
energy feeders and predators. Vampires naturally out of this awareness 
of these abilities find the need to poesses this energy and so are 
predators for it. I have easily taken to my benefit the mental and 
emotional energy of others thru my own manipulation of it as I am 
around it, and then used this energy for my own use. Here you must 
poesses some psychic and empathic ability that comes with the 
heightened sensory ability that many do not have. I found I had it 
while I was a teen about 30 years ago, not because I was taught to 
look for it, but I found that I had it while around other people.
 
The attraction of the blood energy and elements is more difficult to 
understand with the approach you are taking to this subject. My own 
experience came with accidental cuts and finding I had an attraction 
to the properties of blood. I found that with blood I could use 
whatever is present in it to gain the energy lift that I desired, ie. 
it became a need out of my ability to use it this way. I did not 
easily get sick from it, but then most do not need much of it for 
their satisfaction. I have found that others have a lower threshold to 
ingest it than I do. I think it is easy to get use to the energy and 
elemental properties of blood, maybe leading to an addiction for some, 
but blood because of it's properties easily will sicken anyone.

It is important to understand that vampirism is highly dependent on 
abilities of sensory perception and awareness, which so many do not 
have. It also depends on balance, for too much of this mental and 
blood energy overturn's this balance. I did not "learn" my vampirism.
I dicovered it and so became aware of it thru my discovery of my 
sensory abilities and need to use them. And this dicocery of my 
attraction to blood as a teen. These energy feedings came natural for 
me before I knew about the word "vampirism" and what it means. I have 
since gone on to discover this vampirism. Vampirism so is not just 
given to someone, it comes from the abilities and then needs that are 
largely a part of what you came into the world with and then learned 
to use. My experience bears this..