I call it dynamic antagonism where our bodies have a need for two different substances, but the substances are antagonistic to each other.
In this case, I believe that you will find that Iodine
supplementation reduces lithium in the body, and lithium supplementation reduces Iodine
in the body. I wonder what testing one would need to use to determine this. Where do you look at ? Lithium and Iodine
levels in hair ? Skin ? When analyzing metallic alloys we can heat it to melting so everything gets mixed and a small sample is representative of the whole lot. But with these trace elements it is likely that they concentrate more in some places of the body and less in others. So the place chosen for the assay has to be representative of that of the body.
A daunting task that would be , yes. Easiest way for me to forego all that, is to just supplement myself with small amounts of both. The principle can be applied to many other substances the body needs.