Can Zinc Affect Copper?
High-dose zinc taken for weeks can reduce copper absorption.
The short answer
Taking high-dose zinc for several weeks can reduce copper absorption and increase the risk of copper deficiency.
Why it happens
NIH notes that about 50 mg or more of zinc per day for several weeks can interfere with copper absorption. The usual adult upper limit for zinc is 40 mg per day unless it is used under medical supervision.
What to do
If your total zinc intake is close to or above 40 mg per day, do not keep taking it for weeks without advice. Check the total dose and ask a doctor or pharmacist whether you need an adjustment or monitoring.
When this advice applies
The main concern is the dose and how long it is taken. Zinc and copper from ordinary foods do not need to be deliberately separated.
References
- Zinc — Health Professional Fact SheetNIH Office of Dietary Supplements · 2026
- Copper — Health Professional Fact SheetNIH Office of Dietary Supplements · 2022
Updated July 31, 2026 · How to use this guidance