The GPIO pins can source a maximum of 16mA safely. (In fact you CAN draw more, but this is outside the published specifications.)
I assume you are actually asking about the capacity of the 5V and 3.3V pins on the expansion header. The simple answer is that it varies!
See Raspberry Pi Power Limitations for some analysis. This does not directly mention the Pi Zero which has a minimal power circuit (let alone the Pi Zero W, AFAIK the schematic has not been released).
I am sure that you would be able to draw 80mA, given a decent power supply.