Copper

The essential trace mineral for energy, immunity, and connective tissue — but balance with zinc is critical

Also known as: Copper Bisglycinate • Copper Gluconate • Cupric Oxide • Cu

other Names
Copper Bisglycinate, Copper Gluconate, Cu
primary Benefits
Energy production, iron metabolism, connective tissue, immune function, antioxidant defense
common Dose
1-2 mg daily (especially if taking zinc supplements)
best Form
Copper bisglycinate (chelated, well-absorbed)
timing
With food, separate from zinc by 2+ hours
safety Rating
Safe at recommended doses (toxic in excess)

Overview

Copper is an essential trace mineral that serves as a cofactor for numerous enzymes involved in energy production, iron metabolism, connective tissue formation, neurotransmitter synthesis, and antioxidant defense. The body contains only 75-100mg of copper total, but this small amount is critical for survival. Copper deficiency can mimic iron deficiency (causing anemia), impair immune function, and cause neurological problems. However, copper toxicity is also a concern — Wilson's disease is a genetic condition of copper overload. The most important practical consideration is the zinc-copper balance: high-dose zinc supplementation (>40mg/day) depletes copper by competing for absorption. Anyone taking zinc supplements should consider copper supplementation to maintain the optimal 8:1 to 15:1 zinc-to-copper ratio.

Key Benefits

Energy Production (Cytochrome c Oxidase)

Copper is essential for cytochrome c oxidase, the final enzyme in the mitochondrial electron transport chain. Without copper, cells cannot efficiently produce ATP (cellular energy). Copper deficiency causes fatigue that doesn't respond to iron supplementation.

Iron Metabolism & Anemia Prevention

Copper is required for ceruloplasmin, the enzyme that converts iron to its transportable form. Without copper, iron gets trapped in storage and can't be used for hemoglobin synthesis. Copper deficiency causes anemia that looks identical to iron deficiency but doesn't respond to iron supplements.

Connective Tissue & Collagen

Copper is a cofactor for lysyl oxidase, the enzyme that cross-links collagen and elastin fibers. Without copper, connective tissue becomes weak. This affects blood vessels, bones, skin, and joints. Copper deficiency can cause osteoporosis and vascular problems.

Immune Function

Copper is essential for neutrophil function and the production of superoxide dismutase (SOD), a critical antioxidant enzyme. Copper deficiency impairs immune function and increases susceptibility to infections.

Zinc Balance

This is the most common practical reason for copper supplementation. Zinc and copper compete for absorption via the same transporter (MT). High-dose zinc (>40mg/day) can deplete copper within weeks, causing copper deficiency symptoms. A 1-2mg copper supplement prevents this.

Dosage & How to Take

The RDA for copper is 900 mcg (0.9mg) for adults. The Tolerable Upper Intake Level is 10mg. Most people get adequate copper from diet, but those taking zinc supplements should add 1-2mg copper. The ideal zinc-to-copper ratio is 8:1 to 15:1.

PurposeDoseNotes
General health (RDA)0.9 mg/dayUsually met through diet
Zinc balance (if taking 25-50mg zinc)1-2 mg/dayEssential to prevent zinc-induced copper depletion
Zinc balance (if taking 50mg+ zinc)2-3 mg/dayHigher zinc requires more copper

Best Time to Take

Take separately from zinc supplements — at least 2 hours apart. Zinc and copper compete for the same absorption pathway.

With or Without Food

Take with food to reduce GI upset. Avoid taking with high-dose vitamin C, which can reduce copper absorption.

Forms & Bioavailability

FormAbsorptionBest ForNotes
Copper Bisglycinate (Chelated)HighBest absorption, gentleChelated form with excellent bioavailability and minimal GI upset.
Copper GluconateGoodCommon, affordableWell-absorbed and commonly used in supplements.
Cupric OxideVery LowAvoidPoorly absorbed (only 1-5%). Found in cheap multivitamins. Not recommended.

Side Effects & Safety

Common

  • Nausea (especially on empty stomach)
  • Metallic taste
  • GI upset

Rare

  • Liver damage (at toxic doses >10mg/day)
  • Copper toxicity symptoms: vomiting, diarrhea, liver failure

Contraindications

  • Wilson's disease (genetic copper overload)
  • Liver disease
  • Do not exceed 10mg/day from all sources

Interactions

ZincHigh

Zinc and copper compete for absorption; high-dose zinc depletes copper. Separate by 2+ hours.

Vitamin CLow

High-dose vitamin C (>1,000mg) may reduce copper absorption

IronModerate

Copper is needed for iron metabolism; copper deficiency impairs iron utilization

PenicillamineHigh

Chelates copper; used to treat Wilson's disease. Don't supplement copper if taking penicillamine.

Scientific Research

1990American Journal of Clinical Nutrition

Zinc-Induced Copper Deficiency

Zinc supplementation at 50mg/day for 10 weeks significantly reduced copper status markers and caused copper deficiency symptoms

2007British Journal of Nutrition

Copper and Immune Function

Copper deficiency reduced neutrophil count and function, impairing innate immune defense

Food Sources

Liver (extremely high — 12mg per 3oz)
Oysters
Dark chocolate
Cashews
Sunflower seeds
Lentils
Shiitake mushrooms
Spirulina

Frequently Asked Questions

Medical Disclaimer

This content is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any supplement regimen, especially if you have pre-existing health conditions or are taking medications. The statements on this page have not been evaluated by the Food and Drug Administration.