Vegan food that's often taken by medical staff (5)
I believe the answer is:
pulse
This clue is a double definition.
'vegan food' is the first definition.
(type of food which is vegan)
'that's often taken by medical staff' is the second definition.
(a medic might examine a patient's pulse)
(Other definitions for pulse that I've seen before include "regular bodily motion!" , "Throb, quiver" , "flageolet?" , "Vibration" , "edible seeds of leguminous plants!" .)