Hi, Shrikant, unfortunately, there are currently no blood substitutes that have been approved for human transfusion.  

http://isindexing.com/isi/papers/1416464063.pdf

AS Steingrimur reported that  there  is no  proved blood  constituent  till  the  moment

There are no available blood constituent. It is prudent to use allogenous blood alternatives such as iron, hemostatic drugs, topical agents, intraoperative blood salvage, autologous predeposit.

There has been talks of injectable oxygen while this does not take away the need for blood it  significantly reduce the number of blood units needed. There is also heamopure which is often used for people who can't take blood for religious reasons. 

Hi Valencia, from what I know, Hemopure is modified bovine hemoglobin.

Generally, free hemoglobin (Hb) in the circulation is bad news because the Hb Fe++  can oxidize many molecules. That's why haptoglobin is in the circulation to bind and remove any free Hb.

Do you have information about clinical studies using Hemopure?

Also, Jehovah's Witnesses do not understand hematology and biochemistry.

All of the proteins and cells in your blood have a finite lifetime. After a period, they are absorbed  by the liver or kidneys, cleaved to their individual components and recycled.

This happens in all of us, every day

Blood transfusion have nothing to do with consumption of human flesh.

Blood transfusions administered to trauma victims are not designed to keep them well fed on human flesh, they are done to keep them alive by replacing  their lost blood.

If you are a vampire, then yes, blood is a consumable. But for the rest of us, blood transfusions are procedures that have saved many more lives than prayers.