I'm not claiming whether it is good or bad, just that it is more complicated than many assume, and so the benefits or detriments may be much more case sensitive than a generalized comment permits.
For example, I expect iron is made less bioavailable by oxidizing bioavailable ferrous iron to less bioavailable and less soluble ferric iron (its a known process employed in industry to precipitate iron from waste water, promoted by hydrogen peroxide manufacturers).
The same would apply to several other trace elements such as manganese.
Same comment applies to people dosing Lugols and attributing effects to iodine supplementation when the effects observed may be caused for reasons involving trace elements