A leading medical journal says the world could boost its blood supply from young donors by tapping into social networks like Facebook.

In an editorial on Friday, the Lancet calls for doctors to encourage young people to donate blood, including recruitment drives on Facebook or running advertisements for national blood donation agencies on Google.

Blood transfusions save millions of lives every year, but demand far outstrips supply.

By recruiting young people to donate, officials hope they will then give blood regularly in the future.

”If every blood donor used their Facebook wall to recruit friends…the mismatch between demand and supply could be eliminated,” the Lancet said.