Too much sulfur causes copper deficiency:
Studies of a naturally occurring sulfur-induced copper deficiency in Przewalski’s gazelles
Garlic, onions and eggs are the worst. Sulfites contribute too. You will know you have way too much sulfur (or improperly metabolized sulfur) when your pee smells like sulfur and people say you smell like eggs.
To process sulfur molybdenum and vitamin b6 come up. Salt apparently increases sulfur, with copper, calcium and potassium antagonizing it along with "vitamin b15". ( Selenium Sulfur DRI/RDA, benefits, side effects, overdose, toxicity, requirements )
So those with copper deficiency may be having too much sulfur in their diet. Wines, dried fruits have sulfites added and so on.
Salicylates can hinder the pst pathway and thus interfere with metabolism of sulfur. Coconut oil and aspirin are high sources of salicylates. ( a list of foods Salicylate Foods - sensitivity, intolerances and food list. - ATP Science Pty Ltd )
Thus consuming too many salicylates with your sulfur may interfere with proper metabolism of sulfur, thereby causing elevated levels that hinder copper absorption.
Excessive sulfur also can induce a selenium deficiency, which is necessary for thyroid function.
High caffeine is touted to interfere with the body utilizing vitamin b6, which is needed for sulfur metabolism.
Thus say a high coffee diet with coconut oil and too many eggs with too many dried fruits could induce excessive sulfur leading to these mineral deficiencies.
I am researching this for myself, as I noted extraordinarily negative effects from consuming raw garlic (2 cloves a day) Mind you large quantities of eggs are a staple in my diet, as is coconut oil.
So much to research.
Roger that Jack - I'm always trying to think of more robust systems for diagnosis and qualification. We need better ways to catch the many edge cases out there when we open the Pandora's box of supplementation. Things are much simpler when all inputs are whole foods, but for those of us who want to do better or heal faster: either we're delusional, impatient, or just in need of better systems for real time determination of cause & effect.