Haven't seen drinkable blood, but there are some rather exotic foods, some of which (if you squint a bit) look a bit like blood, among those referenced here:
http://www.epicurisims.com/Foods/weirdyucky1.htmlAlso, Carrigon has made drinkable wine which one could imagine was a bottle o' blood:
http://www.sims2workshop.com/viewtopic.php?t=1030There is also a mod at MTS2 which allows for satisfying hunger via vampire biting:
http://www.modthesims2.com/download.php?t=225894.