Zinc

Zinc (Zn)

Also known as: N/A

Zinc is an essential trace mineral critical for immune support, wound healing, DNA synthesis, and cell division. It must be obtained through diet or supplements, as the body cannot store zinc.

Introduction

Zinc is involved in over 300 enzyme reactions and is integral to immune system function, protein synthesis, wound healing, DNA synthesis, and cell division. It contributes to normal growth and development during pregnancy, childhood, and adolescence, and supports reproductive health. Zinc also plays a role in maintaining skin integrity and vision. Although zinc exists naturally in meats, shellfish, legumes, and whole grains, factors such as dietary phytates can reduce absorption. Zinc status may be marginal in populations with limited animal protein intake or high cereal consumption. Supplemental zinc, available in various forms (gluconate, sulfate, picolinate), helps maintain adequate levels in individuals with increased requirements or limited dietary intake. Maintaining optimal zinc intake supports antioxidant defenses, immune function, and normal cognitive function, while deficiencies impair growth, wound healing, and immunity.

Main Benefits

Supports normal immune function by promoting development and activity of immune cells.
Promotes wound healing through collagen synthesis and cell proliferation.
Contributes to normal DNA synthesis and cell division, supporting growth and development.
Maintains proper sense of taste and smell by stabilizing cell membranes in sensory cells.

Mechanism of Action

Zinc acts as a catalytic, structural, and regulatory ion, serving as a cofactor for hundreds of enzymes involved in DNA and RNA synthesis, protein synthesis, and antioxidant defense. It stabilizes cell membranes and regulates gene expression by binding to transcription factors. In immune cells, zinc influences cytokine production, lymphocyte proliferation, and natural killer cell activity. Zinc also modulates wound healing by regulating inflammatory response, promoting keratinocyte migration, and supporting collagen synthesis. Absorption occurs primarily in the small intestine via specific transporters; intracellular zinc homeostasis is maintained by metallothioneins and zinc transport proteins (ZIP and ZnT families).

Natural Sources

Zinc is found naturally in red meat, poultry, seafood (especially oysters), beans, nuts, whole grains, fortified cereals, and dairy products. Plant sources contain phytates that inhibit zinc absorption.

Examples:

Oysters
Red meat (beef, lamb)
Poultry (chicken, turkey)
Beans (chickpeas, lentils)
Nuts (cashews, almonds)
Whole grains (oatmeal, brown rice)
Fortified cereals
Dairy products (milk, cheese)

Ease of Sourcing from Diet6/10

While zinc is present in many foods, absorption is lower from plant sources due to phytates; supplementation may be needed in at-risk groups.

Deficiency Symptoms

Zinc deficiency can lead to impaired immune response, delayed wound healing, growth retardation, hair loss, diarrhea, and taste or smell disturbances. Severe deficiency in children causes stunted growth and increased infection risk.

Common Symptoms:

Impaired immune function
Delayed wound healing
Growth retardation (children)
Hair loss
Diarrhea
Loss of taste or smell

Deficiency Prevalence5/10

Moderate prevalence worldwide, especially in populations with high cereal and low animal protein diets.

Impact of Deficiency7/10

Significant impact on immunity, growth, and wound healing when deficiency is untreated.

Recommended Daily Intake

Recommended Dietary Allowances (RDAs) for zinc vary by age, sex, and life stage. Guidelines from NIH and EFSA ensure adequate intake and prevent deficiency.

Reference Values:

Infants (0–6 months)	2 mg/day
Infants (7–12 months)	3 mg/day
Children (1–3 years)	3 mg/day
Children (4–8 years)	5 mg/day
Boys (9–13 years)	8 mg/day
Girls (9–13 years)	8 mg/day
Males (14–18 years)	11 mg/day
Females (14–18 years)	9 mg/day
Men (19+ years)	11 mg/day
Women (19+ years)	8 mg/day
Pregnant teens (14–18 years)	12 mg/day
Pregnant adults (19–50 years)	11 mg/day
Lactating teens (14–18 years)	13 mg/day
Lactating adults (19–50 years)	12 mg/day

Sources for RDI/AI:

These values are general recommendations; individual needs may vary. Consult a healthcare provider for personalized guidance.

Effectiveness for Specific Focuses

Immunity Support9/10

Zinc is essential for immune cell development and function; deficiency impairs immunity.

Safety Information

Potential Side Effects

Nausea
Vomiting
Abdominal cramps
Metallic taste

Contraindications

Wilson’s disease
Hemochromatosis (iron overload conditions)
Hypersensitivity to zinc or supplement components

Overdose Information

Overdose Risk Level6/10

High zinc intake can cause gastrointestinal upset, interfere with copper absorption, and affect immune function.

Chronic intake above UL can lead to copper deficiency, anemia, neutropenia, and neurological issues. Acute ingestion may cause nausea, vomiting, diarrhea, and abdominal pain.

Documented Overdose Symptoms:

Nausea
Vomiting
Diarrhea
Abdominal cramps
Copper deficiency
Anemia

Toxicity Thresholds: UL: 40 mg/day for adults (Source: NIH)

Excess zinc from supplements can cause toxicity; dietary zinc from food alone is unlikely to cause adverse effects.

Interactions

Drug Interactions:

Antibiotics etracyclines, quinolones, Zinc can chelate with these antibiotics, reducing their absorption, administer supplements 2–4 hours apart.
Penicillamine Zinc may decrease penicillamine efficacy, separate by at least 2 hours.
Diuretics e.g., thiazides, May increase zinc excretion, potentially lowering zinc levels.

Drug Interaction Risk6/10

Moderate risk; timing and monitoring can mitigate interactions.

Other Supplement Interactions:

Copper High zinc intake inhibits copper absorption, risking deficiency.
Iron Excess zinc may compete with iron absorption when taken concurrently.

Supplement Interaction Risk7/10

High zinc doses can significantly impact copper and iron status, monitoring recommended.

Individuals with impaired copper status, gastrointestinal disorders, or chronic illness should consult a healthcare provider before high-dose zinc supplementation. Avoid prolonged high intake without monitoring.

Forms and Bioavailability

Common zinc supplement forms include zinc gluconate, zinc sulfate, zinc acetate, and zinc picolinate. Bioavailability varies: zinc picolinate and acetate are generally more bioavailable.

Zinc Picolinate

Highly bioavailable form that enhances zinc uptake in cells.

Relative Bioavailability9/10

Shown in studies to increase serum zinc more effectively than other forms.

Preferred for correcting deficiency.

Zinc Gluconate

Well-absorbed form commonly used in lozenges and supplements.

Relative Bioavailability8/10

Widely studied and effective for immune support.

Often found in cold lozenges.

Zinc Sulfate

Effective but may cause more gastrointestinal upset than picolinate or gluconate.

Relative Bioavailability7/10

Absorbed well, but tolerability is lower.

Available in prescription and over-the-counter forms.

Zinc Acetate

Used in lozenges; may shorten cold duration by increasing plasma zinc.