Blood which has been imbibed by a Vampire and absorbed into their system becomes a magickal fluid known as Vitae. Imbued with the Vampire's own magickal powers, it can be used in turn to convert a living human into a Ghoul, or a dying human into a Vampire Childe, or a dying werecreature into an Abomination. It is a potent ingredient in the thaumaturgical blood magick practiced by Clan Tremere and some darker-minded mages. It is also the centerpiece of many blood-bonding rituals of the Sabbat and certain Vampire-inspired cult religions. Some say the "blood of Christ" wine shared in the Christian Liturgy was inspired by Vampiric vitae, others that the Vampiric ceremonies are but pale imitations of the Chrisitan tradition. On Wilke's Star and Van Diemen, Vitae is even occasionally used in such a manner in services of the local branches of the Cult of the Emperor, although this practice is officially condemned by the cult hierarchy. The forbidden Vampiric rite of Diablerie of course involves drinking all the Vitae in a vampire, killing them, and transferring some of their power and even memories into the drinker. Vampires of a higher Generation can use this method to effectively lower their generation number, if they drink the vitae of a lower-generation vampire, and thus increase their potential power by bringing them closer to the blood of Caine.
Within a vampire, the vitae circulates much like blood, but in a slow continuous current rather than with a pulse. Vampires can "burn blood" to power some of their special abilities, as long as their supply of vitae holds out, and their supply also slowly diminishes a little bit every night of their unlives, forcing them to drink fresh blood to replenish it. Ghouls not only must drink a little bit of blood every few days to survive, they must drink at least a little vampiric vitae once a month or so as well, or they begin to age and eventually die. Blood drunk by a Ghoul, or flowing in their veins, does not become true Vitae, although some particularly powerful ghouls can inject themselves with vitae and carry it in their blood stream until needed to feed or create another ghoul on behalf of their vampiric master, squeezing it out when needed. Some ghouls use this trick to preserve vitae for thier own survival when on errands for their master that require long-distance or long-duration travel.
Vitae is toxic to K'Nes, which is why K'Nes cannot be turned into ghouls or vampires - they would die in the attempt. It has not yet been established what effect, if any, vitae has on Jurvain, Horadrim, or Vulthra.