If I recall correctly, gold is extremely unreactive as far as metals go -- I'd imagine that it may just be more-or-less biochemically neutral.

Edit: I may be dead wrong. https://en.wikipedia.org/wiki/Organogold_chemistry

I think you're correct. Pure gold is extremely hard to dissolve or oxidize. There's three common methods, using a mercury amalgam(which is an alloying, so the gold is still unreacted), cyanide, or a mixture of hydrochloric and nitric acid called aqua regia.

According to https://en.wikipedia.org/wiki/Gold#Toxicity, the gold ion is toxic, but there are no chemical processes known to occur in the human body that can solubilize metallic gold.

> Yes, empirically, I guess at least gold cannot be too or immediately toxic

Gold goes out from the body unchanged from how it went in.

An attribute capitalized upon by this product http://incrediblethings.com/food/this-gold-pill-makes-you-po...