In short supply
Definition 1 of 1
Pro Tip 1/3Context Importance
Understand the context to assess urgency. 'In short supply' suggests a serious lack or immediate need. 
During the drought, clean water was in short supply.
Pro Tip 2/3Emotional Weight
The phrase can carry concern or worry, regarding a situation where the item is needed. 
Patients were anxious as blood donors were in short supply.
Pro Tip 3/3Economic Impact
Mentioning something is 'in short supply' may imply its price could increase due to high demand. 
With masks in short supply, their prices skyrocketed.