Good answer however in oldschool Vamps such as these the vitamin D is apparently present as there are a few scenes where Vlad is a Daywalker. the head chopping and stake, yeah that would kill me  no doubt.

I guess the possibility is however that if we as atheists deny the soul concept, then in the religious condentations would make us vampires as we stand, despite the heart beat. 

yeah so now I am just having fun with the Philosophical stand and not the scientific fact that you mentioned here, which I fully agree with.

    The myth of vampirism actually stems from a rare genetic disorder called poriphyria. It involves a lack of hemoglobin, leading to pale skin, extreme sensitivity to light, degeneration of the tissue around the lips and gums (leading to pronounced, sharp teeth and pointed ears), excess body hair, and the need for occasional blood transfusion to avoid extreme anemia.

 People with this disease would have been outcasts in the middle ages, having to live inside small, lightless huts during the day to avoid exposure to light and retain their energy, and would have been frightening to see. Medieval doctors attempted to treat this condition with garlic, a common herb, and this is probably where the garlic myth came from.

Porphyria has to be rough.

It's sister syndrome is spherocytosis. You're okay until you get a sunburn then it's four days while your whole body regrets itself. 

Check Vampire: Bloodlines as well, great fun for RPG and vampires lovers

      Google these two real monsters for some nightmeres,

 Elizabeth Bathory: born into one of the oldest and wealthiest families in Transylvania.

Truly, she was evil enough to be recognized as one of the original "vampires" who later inspired Bram Stoker to write the legend of Dracula -- but unlike Stoker's story, she was real. In order to improve her complexion and also to maintain her failing grasp on her youth and vitality, she slaughtered six hundred innocent young women. She drank and bathed in their blood.

Vlad Dracula, the Impaler, notorious for his sadism, killed up to 500,000. He showed no mercy and tortured his enemies before killing them.

Committing atrocity after atrocity against his own people, Vlad Dracula became known for his inhuman cruelty. The tortures he employed included amputation, eye gouging, strangulation, nails in heads, burning at the stake, cutting off of noses and ears, mutilation of sexual organs (especially in the case of women), scalping, skinning, exposure to the elements or to wild animals, and boiling alive.

Dracula however developed a particular taste for subjecting his victims to impalement, which was known to be one of the most agonizing ways of dying imaginable. As his victims twisted and twitched as they neared death, Dracula was known to say, "Oh, what great gracefulness they exhibit!"

The horror Dracula put his impaled victims through is nearly incomprehensible.

Despite the atrocities committed against Wallachians and Transylvanians alike, Dracula was seen as a hero of Christianity by many Romanians.