Calgary's human milk bank has become so successful it’s now sending product to almost every neonatal intensive care unit in the province and hospitals across the country.

The Calgary Mothers’ Milk Bank has seen a 40 per cent increase in demand for its breast milk since it was created in 2012.

The not-for-profit organization takes in donated milk from breastfeeding mothers, screens and pasteurizes it and then distributes it for premature babies and others who need it.

The bank is now hiring more staff and needs to move to a bigger space.

Executive director Jannette Festival says they are busy but happy to know the bank is providing a needed service.

“Sometimes we just have moms and dads that come in and say, ‘We just love what you're doing and thank you.’ So it's a very good feeling,” she said.

Hospitals like being able to provide the milk, she said.

“They've seen an increase in the health of babies and they've seen great response, so I believe that has contributed to an increase in the use of donor human milk.”

The biggest challenge is getting enough donors to keep up with demand, Festival said.