The jews who still live under law don't eat pork, etc, just as they had been commanded, and they also don't eat blood. Reason would dictate to consider their stance on the blood issue if blood transfusions were a violation of eating blood. I find it interesting the society tells it's members that if blood transfusions were available in bible times they wouldn't have taken them, yet since they are still following law, lets see what they have to say about it.
Here are a few quotes from jewish sources about blood transfusions I found....
"There is nothing in Jewish law that would preclude a person from benefiting from a blood transfusion (or donating blood, for that matter).
Furthermore, according to Jewish belief, saving a life is one of the most important mitzvot (commandments), overriding nearly all of the others. (The exceptions are murder, certain sexual offenses, and idol-worship—we cannot transgress these even to save a life.) Therefore, if a blood transfusion is deemed medically necessary, then it is not only permissible but obligatory."
Islamic since they also don't do blood or pork says this, "Sheikh Ibrahim Desai states, the permissibility of blood donation or blood transfusion is determined by the following conditions:
a) The donor should donate his blood willingly. If he is compelled to do so, then it is not permissible;
b) There is no danger to his (the donor's) life or health;
c) It must be clarified by the doctor that blood transfusion is necessary otherwise the life of the patient will be at stake; i.e. the recovery can not be possible without blood transfusion.
d) It is not permissible to sell one's blood or to pay the blood donor. However, if one is desperate for blood (to save his life) and the only means to obtain it is to purchase it, then it is permissible to pay for the blood. [In this case, it is only the one who asks for the money that will incur the sin]. "
" Jewish thought makes very clear that blood is life and that people must recognize the life-affirming power of blood. For instance, one is not allowed to consume blood as food or drink, and if one deliberately sheds the blood of wild animals or fowl when slaughtering food, the blood must be covered as a sign of respect.
Since human blood cannot be consumed, one might ask whether blood transfusions are permitted. The answer, simply, is yes. One may both give and receive blood transfusions because Judaism puts the utmost importance on preserving life. For those who need it, Ezekiel’s words: “By your blood shall you live” (Ezekiel 16:6) has some very literal implications."