Long-term zinc supplementation can deplete copper levels.
Zinc induces metallothionein production in intestinal cells, which binds copper and prevents its absorption.
If supplementing zinc long-term (>25mg/day), consider adding 1-2mg copper or take a zinc supplement that includes copper.
Take zinc and copper at different times to prevent zinc from blocking copper absorption.
Zinc induces metallothionein which traps copper. Taking them at different times reduces this effect.
If supplementing zinc above 25mg/day, take a copper supplement (1-2mg) at a separate meal.
Reference values for safe daily intake of these supplements.
Chronic high intake can cause copper deficiency and immune dysfunction.
Liver toxicity risk at high doses.