I studied geochemistry and mathematics before dropping out my senior year at ivy league and there are metal impurities in literally everything. It comes down to how pure you want it, as most chemicals have trace amounts of the abundant earth metals and many of the are good for you in small amounts( Al, Mg, Zn, Li, etc, are common in sports drinks and vital electrolytes). Though it is man made, most of the elements could be found naturally. Carbon and amino chains are everywhere on this planet, a petri dish of biogeochemical reactants and products