City life has left people struggling to find the time to donate blood, according to the Irish Blood Transfusion Service (IBTS).
IBTS donor services manager Kieran Healy says busy lifestyles meant less people were making the lifesaving trip in urban places despite easier access to clinics.
"We are up against it, it is a real challenge in cities, Dublin particularly. People are less socially minded, there is less community spirit in urban areas rather than rural," he said.
Mr Healy revealed that people in Dunleer, Co Louth, which has a population of about 1,000, donated 85 units of blood to the IBTS mobile clinic in one day.
He said this compared with around 100 units collected in the IBTS's two centres in Dublin during the same 24-hour period - despite a population of about 1.2 million.
"We should be collecting upwards of 200 units a day in Dublin," he said, with two clinics in the capital at D'Olier Street and Stillorgan.
Mr Healy revealed the IBTS has been challenged in meeting demands for blood this year due to a number of factors including the stringent regulations introduced to protect against contracting the human form of mad cow disease, vCJD.
"The blood supply this year has been challenged in meeting all demands," Mr Healy said. "I am certainly in no way complacent, the demands in recent weeks from hospitals has exceeded our ability to supply. "We wouldn't be comfortable with our supply at the moment."
He said the new restrictions meant that from last year anyone who had spent a year or more in Britain between 1980 and 1996 could not give blood. Mr Healy said: "We had research carried out last year that as a consequence of our referrals we would have lost up to 9% of our donors."
Over 3,000 blood donations are needed each week to keep up with the demand of supplies for medical operations, births, newborn babies, cancer patients and others. "If we continue to not supply hospitals with their demands that has consequences for medical procedures. No one would want a medical procedure curtailed because of inadequate supply," he said. "The blood supply is the oil or engine of the health service and the only way we can get it is the generosity of people, we are depending on their altruism."