Well Zoe you used my answer! BSM is one the best possible source of copper I know of along with kelp and Apple Cider vinegar that your body recognizes as naturall foods thta are easily assimulated! Copper is essential and ole timey cattlemen/farmers knew this when they copper doted thier plows !
Copper deficiency is known now to to be the culprit behind the spongiform diseases along with the toxin organochloride or organphosphates!Possibly the cause of CFJ Creutzfeild Jacobs disease and even poliomyelitis!