I think the common term for gold poisioning is greed.

Not gold, but similar: consuming silver has a long history, continuing right up to this day, in spite of the fact that it just seems to ruin your complexion. http://news.bbc.co.uk/2/hi/americas/2297471.stm

It's quite possible the gold was alloyed with lead or other toxic/poisonous heavy metals and consumed. Though I have myself not heard of kings ingesting gold directly, though I am sure it has been done for a variety of dubious reasons.