What Do Zinc, Selenium, and Copper Do for the Body?

November 26, 2025 •

3 min read

Did you know that trace elements zinc, selenium, and copper form a synergistic trio essential for the body's defense against oxidative stress? These vital micronutrients play distinct yet interconnected roles in maintaining cellular integrity, bolstering immune function, and supporting numerous metabolic processes that are critical for overall health.

Quick Summary

Zinc, selenium, and copper are trace elements essential for powerful antioxidant defense, immune system regulation, and metabolic health. A balanced intake is key to prevent deficiencies, toxicity, and maintain cellular integrity.

Key Points

Antioxidant Trio: Zinc, selenium, and copper work together as cofactors for key antioxidant enzymes, protecting cells from oxidative stress and damage.
Immune Defense: All three minerals are vital for maintaining a strong and responsive immune system, with zinc being particularly important for immune cell function.
Metabolic Hub: Zinc supports over 300 enzymes involved in metabolism, while copper aids in energy production and iron transport.
Thyroid Regulation: Selenium is critical for the production and metabolism of thyroid hormones, impacting overall hormonal balance.
Structural Support: Copper plays a crucial role in maintaining the structural integrity of connective tissues like collagen and elastin.
Balance is Key: Excessive intake of one mineral, particularly zinc, can interfere with the absorption of another, such as copper, underscoring the need for balanced nutrition.

The Trio of Trace Minerals: An Overview

Essential trace minerals like zinc, selenium, and copper are required by the body in very small quantities, yet they are fundamental to countless biological processes. Functioning primarily as cofactors for crucial enzymes, they are indispensable for maintaining optimal health. Their combined action is particularly important for the body's antioxidant defense network, protecting against damage from reactive oxygen species (ROS). Understanding the unique contributions of each mineral is key to appreciating their collective importance.

The Diverse Roles of Zinc

Zinc serves as a cofactor for over 300 enzymes, supporting immune function, wound healing, metabolism, and DNA synthesis. It is especially vital during growth and development. Zinc also contributes to antioxidant activity as part of Cu/Zn-superoxide dismutase (Cu/Zn-SOD).

Dietary Sources of Zinc

Meat (especially red meat)
Legumes
Nuts and seeds
Dairy products
Fortified cereals

The Antioxidant Power of Selenium

Selenium is incorporated into selenoproteins, which are potent antioxidants essential for thyroid function and protecting against oxidative damage. The selenoenzyme glutathione peroxidase (GPx) neutralizes harmful hydrogen peroxide. Selenium also helps regulate immune function and is important for reproductive health.

Dietary Sources of Selenium

Brazil nuts (one of the richest sources)
Seafood (tuna, cod, shellfish)
Organ meats
Poultry and beef
Eggs

The Structural and Metabolic Functions of Copper

Copper is essential for various functions, including antioxidant support as a component of Cu/Zn-SOD. It is vital for forming connective tissues, involved in iron metabolism, energy production, and nervous system function.

Dietary Sources of Copper

Organ meats (liver)
Shellfish
Nuts and seeds
Whole grains
Legumes

The Interplay Between Zinc, Selenium, and Copper

These minerals work together, particularly in the antioxidant system. Cu/Zn-SOD (containing zinc and copper) dismutates superoxide radicals, and selenium-dependent GPx neutralizes the resulting hydrogen peroxide. A deficiency in any of these can disrupt this defense. High zinc intake can also interfere with copper absorption.


Feature	Zinc	Selenium	Copper
Primary Function	Cofactor for >300 enzymes, immunity, DNA synthesis	Selenoprotein synthesis, potent antioxidant, thyroid function	Enzyme cofactor, connective tissue, iron metabolism
Antioxidant Role	Part of Cu/Zn-SOD, neutralizes superoxide	Part of GPx, neutralizes hydrogen peroxide	Part of Cu/Zn-SOD, neutralizes superoxide
Immune Function	Supports immune cell development and function	Modulates immune cell function and inflammation	Supports immune cell function (SOD)
Primary Deficiency Symptom	Impaired immune function, delayed wound healing, poor growth	Thyroid issues, Keshan disease, weakened immunity	Anemia, neutropenia, impaired connective tissue
Dietary Interaction	High intake can inhibit copper absorption	Works synergistically with other antioxidants	Absorption inhibited by high zinc intake

Navigating Mineral Interactions and Supplementation

Due to the interactions between these minerals, especially zinc and copper, it's generally best to get them from a balanced diet. If supplementation is considered necessary, consult a healthcare professional to determine the correct dosage and avoid imbalances. You can find more information on mineral interactions and health from resources like the MDPI journal.

Conclusion

Zinc, selenium, and copper are a vital team for cellular health and well-being. They are essential for antioxidant defense, immune function, and metabolism. A diverse, nutrient-rich diet supports the optimal function of this trio. Maintaining a balance is critical, as both too little and too much can lead to negative health outcomes.

Frequently Asked Questions

Zinc is a cofactor for over 300 enzymes and is crucial for immune function, DNA synthesis, protein production, and wound healing.

Selenium's primary benefit comes from its antioxidant role as part of selenoproteins like glutathione peroxidase (GPx), which protects cells from oxidative damage. It is also essential for proper thyroid function.

Copper is involved in energy metabolism, connective tissue formation, and iron metabolism. It also acts as an antioxidant in the Cu/Zn-superoxide dismutase enzyme.

These minerals are linked in the body's antioxidant defense system. Zinc and copper work in the enzyme Cu/Zn-SOD, and selenium works in GPx, to neutralize free radicals in a cascading process.

Yes, chronic high-dose zinc supplementation can inhibit the absorption of copper, potentially leading to a copper deficiency and related health problems like anemia.

Zinc can be found in red meat, legumes, and nuts. Selenium is abundant in Brazil nuts, seafood, and organ meats. Copper is present in organ meats, shellfish, and whole grains.

Most healthy individuals can get sufficient amounts of these minerals from a balanced diet. Supplementation should be discussed with a healthcare professional to avoid mineral imbalances or toxicity, especially with higher doses.