>>12422504Yes your bones are very much a living thing and not just some mineral. If you wanted titanium in your bones you would need an entire new biochemical apparatus that would transport titanium ions and incorporate them in your bones.
Also titanium is a 3d metal- it is much more chemically versatile than calcium and would require specific proteins that would keep it in desired oxidation state not to mention that your bones would need so much titanium that your body couldn't handle in form of transportable ions (due to extensive redox III-IV reactions).
From your post I assume you talk about metallic titanium that is biologically inert, yes but you would need to consume titanium from your enviroment somehow which I doubt there is much of it available, unlike calcium. Titanium would just be dispersed in nature as oxide or (FeTiO3 from which a TiO2 is made) and I don't think your stomach acid would be sufficient to dissolve it anyway to be used.
Therefore I would say that these bones containing pure metal are biologically unobtainable.
If one would consider on the other hand bones where calcium (II) is substituted for titanium (IV), again your body would need to create a new organic matrix to bind to the inorganic material and it's particular crystal dimensions. But in this case there is no reason to believe an inorganic titanium salt should posess any better physical properties than an apatite.
