Canadian Blood Services is struggling to replenish a critically low supply because of the ongoing COVID-19 pandemic.
The organization operates a national inventory of blood that is shifted around the country.
It says it has had the smallest donor base in a decade.
Spokesman Rick Prinzen says it's because the number of people who donate regularly has dropped by 31-thousand since the pandemic began.
He says that's put a strain on the system and the organization needs to attract 100-thousand new donors this year.
Only about 400-thousand of Canada's 37-million population give blood on a regular basis.
Prinzen says this is also a slow time of year as Canadians leave on vacations and cancel appointments.