Voyager has replicators, including Industrial Replicators for Engineering and stuff. They should be able to absorb the raw energy from...virtually anything in space (Suns, Nebulae, random space radiation) to power the Replicators meaning it has just as much a "Healing Factor" as those Living Ships.
That makes perfect sense. Take matter, convert it to energy, replicate whatever. It would seem Voyager should be sustainable forever.
EXCEPT, at the beginning of the series they made a big deal about energy conservation because it was a nice plot device at the time. Any person with half a brain can figure out deuterium is heavy hydrogen and should be readily available or replicable, but they had to use it as a plot device. When the energy shortage wasn't convenient, they didn't even acknowledge it. The problem was consistency.