Just like if you take some extra Zinc (30mg-50mg picolinate) for a variety of reasons - you have to take a bit of copper with it, or eventually your copper supplies will be drained and start causing issues.
I’m not 100% sure if it was zinc but I supplemented zinc for like a week then had the worst constipation of my entire life. Like, wife had to run to the pharmacy to resolve it while I cried in agony sort of bad. So yeah, be careful with how you supplement!