My initial guess would be that this superstition arose only in France, in connection with the Tarot image, so 16th century at the earliest. This is coincidentally the earliest time we find evidence of a superstition about the number 13 - 13 at a table being unlucky, mentioned by Montaigne. See my post on the subject here -
http://ludustriumphorum.blogspot.fr/200 ... -card.html
For documentary evidence, I'm not sure what you might be looking for. Something like a text that contains a personification of Death, with a note that reads something like "He/She who shall not be named", "He without a name", etc.?
Excepting Tarot de Marseille style packs from the 17th century onward, there seems to be no reticence to name death, "Death", that I recall.