Ludzia is rather rare, as of 1990 there were 44 Poles by that name, living in the provinces of Nowy Sacz (37), Olsztyn (3), and Walbrzych (4). Unfortunately, I don't have access to further details such as first names and addresses, so what I've given here is all I have. This name could come from the root lud, "people, folk," or it could have started as a short form or nickname of names such as Ludwik (Louis), or of ancient pagan Polish names with that root _lud) as their first element, e. g., Ludomir ("peace" + "people"), etc. To be honest, I think a connection with either Ludwik or one of those Ludo- names is the likely one.