Canadian Blood Services says it needs more donors in the Ottawa area if it wants to avoid a blood shortage in the capital region.

The non-profit organization put out a national call for blood donations last week, saying winter storms caused donor clinics and appointments to be cancelled across the country.

Ottawa is also facing a potential shortage.

Canadian Blood Service's local manager said Tuesday that hospitals need an average of about 5,000 donations every two weeks. However, only about 2,700 blood-donor appointments are booked for the upcoming two weeks.

Mary Ann St. Michael says they've been 'struggling' the last few weeks with people's busy holiday schedules and winter storms keeping donors away. (CBC)

"We're getting to the point where there could be a [blood] shortage," said Mary Ann St. Michael, at a clinic at Ottawa City Hall.

"We don't have a shortage right now. We have a shortage of people making an appointment."

St. Michael said that in addition to the usual hectic holiday schedule, two additional issues are causing this December to be a worse than in recent years: bad winter weather; and the recent decision to change the minimum time between donations for women from eight weeks to 12 so they can better replenish their iron levels.

St. Michael couldn't say at what point a donor shortage would trigger a blood shortage.

Canadian Blood Services has a permanent donor clinic at its headquarters at 1575 Carling Ave. in Ottawa and 850 Gardiners Road in Kingston.

Wednesday there is a clinic at the Smiths Falls Civitan Club on Highway 15.