IngredientsChemical identity: Zinc (chemical symbol Zn, atomic number 30) is a bluish-white transition metal belonging to Group 12 of the periodic table. In biological and nutritional contexts it is classified as an essential trace element — an inorganic mineral that the human body cannot synthesize and must obtain from dietary or supplemental sources. Its biologically active ionic form is the divalent cation Zn²⁺.
Zinc is found in cells throughout the body. Zinc functions as a component of various enzymes in the maintenance of the structural integrity of proteins and in the regulation of gene expression.
Natural dietary sources: Oysters contain more zinc per serving than any other food, but red meat and poultry provide the majority of zinc in the American diet. Shellfish, beef, and other red meats are rich sources of zinc; nuts and legumes are relatively good plant sources of zinc. Beans, nuts, whole grains, eggs, and dairy products provide some zinc.
Common supplemental forms: Forms of zinc that are commonly found in dietary supplements include zinc sulfate, zinc acetate, and zinc gluconate. Zinc is available in supplements that only contain zinc, supplements that contain zinc in combination with other ingredients, and in many multivitamin/mineral products. In addition to standard tablets and capsules, some zinc-containing cold lozenges are labeled as dietary supplements. Zinc is also found in some denture adhesive creams and over-the-counter products, including those labeled as homeopathic medications for colds.
Elemental zinc content of compound forms: The Supplement Facts panel on a dietary supplement label declares the amount of elemental zinc in the product, not the weight of the entire zinc-containing compound. For reference, zinc gluconate (100 mg) yields approximately 14 mg elemental zinc, zinc sulfate (220 mg) yields approximately 50 mg, and zinc glycinate (50 mg) yields approximately 12.5 mg of elemental zinc.
Zinc absorption by young adults from supplemental zinc citrate is comparable with that from zinc gluconate and higher than from zinc oxide. Research has not determined whether differences exist among forms of zinc in absorption, bioavailability, or tolerability.
The medicinal use of zinc compounds predates the formal isolation of the metal by millennia. Centuries before zinc was discovered in the metallic form, ores used for making brass and zinc compounds were used for healing wounds and sore eyes.
Ancient Rome: One of the oldest known medicinal uses of zinc dates to 140 BCE, with the discovery of zinc carbonate pills aboard the Roman ship Relitto del Pozzino. These pills were used to treat eye ailments and highlight zinc's early pharmaceutical applications.
Ancient Egypt and Persia: Zinc oxide, derived from the heating and evaporation of metallic zinc, served medicinal purposes across various cultures. Ancient Egyptians used it as a salve, while the Persians employed it in eye ointments.
Ancient India (Ayurvedic tradition): The Charaka Samhita medical text (circa 500 BCE) mentions zinc oxide (pushpanjan) produced by oxidizing metal, used as eye ointment and wound treatment. By 400 BCE, Kautilya's Arthasastra referred to burning rasa (zinc-containing metal) for eye salve production. The Charaka Samhita references a metal that produces pushpanjan (zinc oxide) when oxidized. Zinc mining in Zawar, near Udaipur, began during the Mauryan period (circa 322–187 BCE), but metallic zinc production appears to have started around the 12th century CE. A long tradition of Ayurvedic medicinal system, alchemy, and traditional technologies prevalent in India resulted in the innovation of zinc distillation process.
Industrial-era recognition: Zinc was recognised as a separate metal in Europe in 1546. In 1743, the first European zinc smelter was established at Bristol in the United Kingdom. The nutritional essentiality of zinc in humans was not established until the 1960s through the work of Ananda Prasad, who documented classical zinc deficiency in populations in the Middle East.
Unlike botanical supplements that contain diverse phytochemicals, zinc is a single elemental mineral. Its biological activity derives entirely from the chemical properties of the Zn²⁺ ion.
Zinc is required for the activity of more than 300 enzymes, covering all six classes of enzymes. Zinc is associated with many metalloenzymes: cytoplasmic enzymes, e.g., superoxide dismutase and phosphodiesterase; mitochondrial enzymes, e.g., cytochrome oxidase and pyruvate carboxylase; nuclear enzymes, e.g., DNA and RNA polymerase; and enzymes of the Golgi apparatus, e.g., peptidase and mannosidase. Zinc metalloenzymes are found in all 6 enzyme classes (oxidoreductases, transferases, hydrolases, lyases, isomerases, ligases) and therefore engage in all metabolic processes (proteins, carbohydrates, fats, nucleic acids, etc.).
Zinc ions are components of structural and regulatory proteins, including transcription factors, and form "zinc fingers" — sequences enabling the binding of transcription factors to DNA. Zinc is incorporated into about 10% of all human proteins, and well over 300 enzymes are known to require Zn²⁺ for catalytic or structural functions.
At the level of the cell nucleus, zinc can induce gene expression through the structural stabilization and functional regulation of various immunologically important transcription factors. It contributes to chromatin decondensation and the formation of microtubules within the karyokinetic spindle, stabilizes the DNA double helix, and facilitates the transformation of a single DNA strand into a double strand. The body also uses zinc to make DNA (the genetic material in cells) and proteins.
For more than 50 years, it has been known that zinc deficiency compromises immune function. A network based on ZnT and ZIP proteins for transport and metallothionein for storage tightly regulates zinc availability, and virtually all aspects of innate and adaptive immunity are affected by zinc. In vivo, zinc deficiency alters the number and function of neutrophil granulocytes, monocytes, natural killer (NK)-, T-, and B-cells. T cell functions and balance between the different subsets are particularly susceptible to changes in zinc status.
Zn²⁺ can reversibly inhibit membrane phosphodiesterase (PDE) and reduce PDE mRNA expression, which decreases the production of the inflammatory cytokines tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 beta, resulting in anti-inflammatory function. Zinc supplementation in vivo has been shown to protect mononuclear cells against oxidative stress. Zinc negatively regulates gene expression of inflammatory cytokines such as TNF-α and IL-1β, which are known to generate reactive oxygen species, and this may be one mechanism by which zinc functions as an antioxidant in humans.
There are numerous physiologically relevant interactions between zinc and various hormones (e.g., testosterone, adrenal corticoids, insulin, growth hormone), whereby production, storage, secretion, and hormone receptor interactions can all be involved.
Zinc absorption occurs within the small intestine, and the absorbed zinc is released in portal circulation through transporters. Small intestinal perfusion studies in humans have shown that the sites of maximal absorption of zinc are the duodenum and the jejunum.
Zinc bioavailability (the fraction of zinc retained and used by the body) is relatively high in meat, eggs, and seafood because of the relative absence of compounds that inhibit zinc absorption and the presence of sulfur-containing amino acids (cysteine and methionine) that improve zinc absorption. Zinc in whole-grain products and plant proteins is less bioavailable due to their relatively high content of phytate, which inhibits zinc absorption.
A zinc absorption of 10–15% is estimated from diets containing mainly unrefined cereal grains or legumes with negligible amounts of animal proteins. For comparison, a mixed animal and plant product diet has an average zinc bioavailability of 20–30%, whereas a diet with ample refined cereals and rich in animal foods would have an average zinc bioavailability of 30–50%.
Phytic acid (phytate) is found in many plant foods and reduces zinc absorption; some researchers have suggested that this increases the zinc needs of vegetarians by up to 50% (Institute of Medicine, 2001). Food processing techniques can mitigate this: the inhibitory effect can be overcome by food-processing techniques that use enzymes or thermal processing to hydrolyse phytic acid. Soaking and sprouting beans, grains, and seeds also reduces phytate.
Taking supplements that contain a substantial amount of iron (≥25 mg) at the same time as zinc supplements can reduce zinc absorption and plasma concentrations of zinc.
The Recommended Dietary Allowance (RDA) for adults is 8 mg/day for women and 11 mg/day for men. These RDA values range from 8 to 12 mg for adults and from 2 to 13 mg for infants, children, and adolescents, depending on age, sex, and life stage.
The median intake from food in the United States was approximately 9 mg/day for women and 14 mg/day for men.
Tolerable Upper Intake Level (UL): The Tolerable Upper Intake Level for zinc is 40 mg for adults, and it ranges from 4 to 34 mg for infants, children, and adolescents, depending on age. The Tolerable Upper Intake Level (UL) for adults is 40 mg/day, a value based on reduction in erythrocyte copper-zinc superoxide dismutase activity. Notably, the European Food Safety Authority (EFSA) defines the tolerable upper intake level as 25 mg per day, whereas the FDA allows 40 mg per day.
Dosages used in specific clinical contexts (as reported in sources):
Zinc deficiency is characterized by growth retardation, loss of appetite, and impaired immune function. In more severe cases, zinc deficiency causes hair loss, diarrhea, delayed sexual maturation, impotence, hypogonadism in males, and eye and skin lesions. Zinc deficiency at any age can cause a loss of taste and smell. In older adults, zinc deficiency can delay wound healing and cause problems with thinking, reasoning, and memory.
Dietary zinc deficiency is quite common in the developing world, affecting an estimated 2 billion people. Consumption of diets high in phytate and lacking foods from animal origin drive zinc deficiency in these populations. Overt human zinc deficiency in North America is not common, and the symptoms of a mild deficiency are diverse due to zinc's ubiquitous involvement in metabolic processes.
At-risk groups: Certain groups of people may have trouble getting enough zinc: people who have had gastrointestinal surgery, such as weight loss surgery, or people who have digestive disorders, such as ulcerative colitis or Crohn's disease. 35%–45% of adults aged 60 years or older had zinc intakes below the estimated average requirement. When investigators considered intakes from both food and dietary supplements, 20%–25% of older adults still had inadequate zinc intakes.
Evidence strength: Strong. The role of zinc supplementation in correcting documented zinc deficiency is well established and underpinned by decades of clinical research.
Interest in zinc lozenges for the common cold arose from an early clinical observation. Interest in zinc lozenges for common cold treatment started from the serendipitous observation that the cold symptoms of a 3-year-old girl with leukemia disappeared within a few hours when she allowed a zinc tablet to slowly dissolve in her mouth instead of swallowing it whole. The benefit appeared to be derived from dissolving (rather than swallowing) the tablet, which implied that zinc may have local effects in the oropharyngeal region. This observation led to a randomized controlled trial, which found that zinc gluconate lozenges significantly shortened colds and increased the recovery rate with a rate ratio (RR) of 3.5 (95% CI: 1.8–6.7) compared to placebo.
Subsequently, over a dozen placebo-controlled trials were carried out with varying results, with the composition of the lozenges and the dose of zinc effectively explaining the variation. In seven RCTs, zinc acetate and zinc gluconate lozenges containing more than 75 mg/day of elemental zinc shortened common cold duration on average by 33% (95% CI: 21%–45%, P = 10⁻⁷).
A Cochrane review of 34 randomized trials of zinc monotherapy versus placebo including 8,526 patients (22 studies in adults and 12 studies in children) reported that zinc has little to no benefit in cold prevention, but may have a benefit in treatment. A meta-analysis including 28 trials (5,446 participants) reported that, compared to placebo, zinc prevented 5 upper respiratory tract infections per 100 person months with a number needed to treat of 20. The study reported that symptoms resolved 2 days earlier compared to placebo and more subjects were likely to remain symptomatic after 7 days without zinc.
Another meta-analysis reported no difference in efficacy between zinc acetate and zinc gluconate lozenges in treatment of colds and no evidence for greater efficacy of daily doses higher than 100 mg.
Evidence strength: Moderate to moderately strong for reduction in duration of cold symptoms when lozenges delivering >75 mg/day of elemental zinc are initiated within 24 hours of symptom onset. The evidence is more mixed and weaker for prevention of colds. High heterogeneity between trials (differing zinc compounds, doses, formulations) limits definitive conclusions.
Children in developing countries often die from diarrhea. Studies show that zinc supplements help reduce the duration of diarrhea in these children, many of whom are zinc deficient or otherwise malnourished. In response to mounting evidence, the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF) issued a global recommendation in 2004, which advised zinc supplementation in addition to oral rehydration solution (ORS) for the treatment of all diarrhea episodes among children under 5 years of age.
A 2023 systematic review commissioned by the WHO, including 38 RCTs, found that zinc supplementation resulted in a greater proportion of children who recovered from acute diarrhea at last follow-up (RR = 1.07; 95% CI = 1.03, 1.1; moderate certainty of evidence) and a reduction in the duration of diarrhea (mean difference = −13.27 hours; 95% CI = −17.66, −8.89; moderate certainty of evidence) compared to placebo.
Most trials of zinc supplementation for diarrhea have been conducted in low-income countries. Zinc supplements might have only a marginal effect on diarrhea duration in well-nourished children. It's not clear whether zinc supplements help treat diarrhea in children who get enough zinc, such as most children in the United States.
Evidence strength: Strong in zinc-deficient or malnourished children in low- and middle-income countries. Evidence is weak for well-nourished children in high-income countries.
Observational evidence suggests that older adults who have higher zinc intakes have a lower risk of age-related macular degeneration. The results from large clinical trials indicate that taking dietary supplements that contain zinc, copper, and certain antioxidants (known as AREDS formulations) slows the progression of age-related macular degeneration among people who are at high risk of developing the advanced form of this condition. AMD is the leading cause of significant vision loss in older people.
There is strong evidence that supplements containing zinc and antioxidants (vitamin C and E) taken once daily slow progression of moderate to severe atrophic (dry form) age-related macular degeneration. Ten-year follow-up data from a randomized trial demonstrate that supplementation with zinc and antioxidants (vitamin C and E and lutein/zeaxanthin) slows progression of advanced forms of macular degeneration.
The original AREDS study used zinc oxide at 80 mg/day; the AREDS2 study found that a reduced dose of 25 mg/day was equally effective. The AREDS formula also includes copper to offset zinc-induced copper depletion.
Evidence strength: Strong. The AREDS and AREDS2 large randomized controlled trials represent some of the highest-quality evidence for any zinc application. This indication is specifically for those at high risk of advanced AMD; the evidence does not support zinc for primary prevention of AMD in the general population.
Zinc helps wounds heal. People who have wounds such as skin ulcers and who also have low levels of zinc might benefit from taking a zinc supplement by mouth. The preponderance of evidence suggests zinc has antibacterial and anti-inflammatory effects and that it may decrease sebum production.
Zinc plays a central role in all phases of wound healing: zinc is a modulator of the wound-repair process, with antioxidant and anti-inflammatory properties. Topical zinc oxide preparations are widely used in wound care. Zinc that is used on the skin is called zinc oxide. Zinc oxide cream, ointment, or paste is put on the skin to prevent conditions such as diaper rash and sunburn.
Evidence strength: Moderate. Evidence is strongest in zinc-deficient individuals. In individuals with adequate zinc status, the benefit of supplemental zinc for wound healing is less certain.
During pregnancy, infancy, childhood, and adolescence, the body needs zinc to grow and develop properly. Mild zinc deficiency impairs growth in children and can be corrected with zinc supplementation. Dietary zinc deficiency has been associated with impaired growth and development in children, pregnancy complications, and immune dysfunction with increased susceptibility to infections.
There is strong evidence that, in developing countries, supplements containing zinc 20 mg and 20 mg iron taken once a week, when given for the first 12 months of life, reduce infant mortality due to diarrhea and respiratory infections.
Evidence strength: Strong for populations with documented zinc deficiency or risk of deficiency (developing-world settings, premature infants, children with malabsorptive conditions).
Zinc has been investigated for acne vulgaris both as an oral supplement and as a topical agent. In acne treatment, zinc has been linked with decreasing sebum production, decreasing anti-inflammatory mediators, and with antibacterial effects on P. acnes, although its role in acne therapy has been seen as controversial. A systematic review in the Journal of Drugs in Dermatology concluded that the preponderance of evidence suggests zinc has antibacterial and anti-inflammatory effects and that it may decrease sebum production.
Evidence strength: Preliminary to moderate. Multiple small RCTs have shown benefit, but zinc is generally considered inferior to established antibiotic and retinoid therapies for moderate-to-severe acne.
Zinc is an essential trace mineral for the normal functioning of the male reproductive system. Zinc is highly concentrated in seminal plasma, and deficiency has been linked to impaired spermatogenesis. Current studies have investigated the relationship between seminal plasma zinc and male infertility but have shown inconsistent results. Some studies report that zinc supplementation in the treatment of infertility could significantly increase the sperm quality of infertile males, while other studies have shown opposing results.
In adult men with zinc deficiency, it causes hypogonadism, where the testes produce less testosterone. This effect happens at the testicular level, not the brain, meaning the signaling from the pituitary gland may be normal but the testes simply cannot respond properly without adequate zinc.
Evidence strength: Preliminary to moderate. Zinc supplementation appears beneficial in men with documented zinc deficiency; whether it benefits men with normal zinc status is not clearly established.
Zinc has been suggested to increase insulin sensitivity. Clinical data on zinc for treatment of diabetes are emerging. A 2019 systematic review and meta-analysis of 32 randomized, placebo-controlled trials (1,700 subjects) using zinc monosupplements or co-supplements in patients with prediabetes or diabetes, obesity or overweight, and pregnant women with prediabetes or diabetes, found a decrease in fasting blood glucose and other glycemic parameters. Some research shows that zinc supplements might help lower blood sugar and cholesterol levels. People with type 2 diabetes often have low zinc levels.
Evidence strength: Preliminary to moderate. The evidence base is growing but heterogeneous, and most trials have been conducted in populations with pre-existing zinc insufficiency. More high-quality trials are needed.
The U.S. Food and Drug Administration (FDA) granted orphan drug designation to zinc acetate for treating Wilson disease to prevent dangerous copper level elevation. In this application, zinc acts by inducing intestinal metallothionein, which preferentially binds copper and blocks its absorption — a pharmacological rather than purely nutritional mechanism.
Evidence strength: Strong (FDA-approved indication).
Getting excessive amounts of zinc can cause nausea, dizziness, headaches, gastric distress, vomiting, and loss of appetite. Doses of 50 mg of zinc or more over a period of weeks can inhibit copper absorption, reduce immune function, and lower high-density lipoprotein (HDL) cholesterol levels; however, it is unlikely that a person would obtain this much zinc from food alone.
Adverse effects of high zinc intake include nausea, vomiting, loss of appetite, abdominal cramps, diarrhea, and headaches. Intakes of 150–450 mg of zinc per day have been associated with such chronic effects as low copper status, altered iron function, and reduced immune function.
Long-term consumption of zinc in excess of the tolerable upper intake level (UL; 40 mg/day for adults) can result in copper deficiency. Using large amounts of denture creams that contain zinc, well beyond what the label recommends, could lead to excessive zinc intake and copper deficiency. This can cause neurological problems, including loss of coordination, numbness, and weakness in the arms, legs, and feet.
Numerous case reports of anosmia (loss of the sense of smell), in some cases long-lasting or permanent, have been associated with the use of zinc-containing nasal gels or sprays. In June 2009, the FDA warned consumers to stop using three zinc-containing intranasal products because they might cause anosmia. Currently, these safety concerns have not been found to be associated with cold lozenges containing zinc.
Certain populations may be at greater risk for zinc deficiency, such as people who have had weight loss surgery, people who have digestive disorders such as Crohn's disease and ulcerative colitis, vegetarians, alcoholics, and those with sickle cell disease. Children with inflammatory bowel disease (IBD), celiac disease, and those receiving long-term proton pump inhibitor treatments are particularly susceptible to zinc deficiency. Zinc deficiency in children with celiac disease and IBD is attributed to insufficient intake, reduced absorption, and increased intestinal loss as a result of the inflammatory process.
Zinc may interact with certain medications, such as quinolone antibiotics, tetracycline antibiotics, and penicillamine.
Health conditions that Zinc may help support.
Zinc (topical and oral) is among the most clinically studied nutrients for acne, with anti-inflammatory, antimicrobial, and anti-androgenic properties. A Cochrane review of 49 RCTs included topical zinc as an evaluated agent, and multiple double-blind trials of oral zinc sulfate have shown significant reductions in inflammatory lesions. Evidence is consistent though effect sizes are moderate.
Zinc is required for the synthesis of adrenal hormones and acts as a cortisol modulator; deficiency elevates serum cortisol levels in animal models. Research supports zinc's role in supporting DHEA production and modulating excessive cortisol output, both key features of adrenal fatigue management.
Zinc is an essential mineral for male reproductive physiology and testosterone synthesis; zinc deficiency is directly associated with reduced testosterone levels. A clinical review (Bandeira Filho et al., Clinical Therapeutics, 2020) confirmed that medicinal zinc doses (50 mg elemental zinc/day) can increase total testosterone and improve sperm count in hypogonadal men. The mineral inhibits aromatase, reducing testosterone-to-estrogen conversion, a mechanism particularly relevant in aging men.
Zinc is a well-established pro-antioxidant micronutrient supported by extensive human clinical evidence. It functions as a structural cofactor for copper-zinc superoxide dismutase (Cu/Zn-SOD), induces the synthesis of antioxidant metallothioneins, and protects sulfhydryl groups in proteins from oxidative damage. Multiple systematic reviews and meta-analyses of controlled clinical trials confirm that zinc supplementation significantly improves markers of the antioxidant defense system, including total antioxidant capacity and reduced lipid peroxidation. Both zinc deficiency and supplementation studies in humans corroborate that maintaining adequate zinc status is essential for robust antioxidant protection.
Zinc, particularly as zinc undecylenate and zinc sulfate, has documented antifungal activity in tinea pedis. Products containing zinc undecylenate became among the most effective early topical antifungal treatments from the 1940s, and zinc undecylenate/undecylenic acid combinations are FDA-recognized OTC agents for tinea pedis. A controlled trial (n=151) showed 88% negative cultures at 4 weeks. A clinical study also compared 15% zinc sulfate with clotrimazole for tinea pedis.
Multiple RCTs and systematic reviews show that zinc deficiency is common in children with ADHD, and supplementation (typically 15–55 mg/day elemental zinc) can reduce hyperactivity and impulsivity scores. Effect sizes are small to moderate and are most pronounced in zinc-deficient populations. A 2021 systematic review of nine RCTs confirmed improvements in ADHD symptom severity with zinc supplementation compared to placebo.
Zinc ions directly neutralize volatile sulfur compounds (VSCs), the primary cause of halitosis, by binding to sulfur moieties and rendering them odorless. Multiple randomized controlled trials using zinc lactate, zinc acetate, and zinc chloride mouthwashes have demonstrated significant reductions in oral VSC levels and organoleptic scores compared to placebo. A 2021 single-blind crossover RCT (n=60) confirmed zinc lactate mouthwash combined with tongue scraping significantly reduced morning breath VSC concentrations (p<0.05).
Zinc is cited by multiple authoritative sources including institutional neurology references and integrative medicine protocols as a supportive nutrient for Bell's palsy. Zinc inhibits HSV-1 replication (a likely etiological agent of Bell's palsy), supports normal nerve function, and has been shown in clinical trials to reduce herpes outbreak duration. Zinc deficiency impairs nerve signal transmission.
Zinc has well-established roles in wound healing and skin repair including blister management. Topical zinc oxide provides wound barrier protection and supports epithelialization. Zinc deficiency has been linked to impaired skin healing and blistering skin toxicity, and zinc supplementation rapidly improved drug-induced blistering eruptions in a 2025 case series.
Zinc is involved in virtually all aspects of insulin metabolism including synthesis, secretion, and utilization of insulin. Meta-analyses show zinc supplementation can improve glycemic parameters in T2DM. It also has a protective effect against pancreatic beta-cell destruction.
Zinc, particularly as zinc oxide, has robust clinical evidence for reducing axillary body odor. A randomized, double-blind, placebo-controlled trial (ZINC-ON, presented at ECCMID 2019, published in Acta Dermato-Venereologica) in 30 healthy volunteers found that topical ZnO application for 13 days significantly reduced odor-producing Corynebacterium spp. and Staphylococcus hominis, and reduced self-perceived malodor compared to placebo. Zinc salts have also been used in deodorant formulations for their odor-neutralizing and mild antimicrobial properties.
Zinc is an essential cofactor for alkaline phosphatase and enzymes critical to bone matrix synthesis and remodeling. Clinical evidence links zinc deficiency with reduced BMD, and supplementation studies suggest zinc supports bone formation markers. It is recognized by the NIH ODS and National Academy of Sciences as important for bone health.
Zinc is an essential trace mineral and cofactor for over 300 enzymes, including those involved in neurotransmitter synthesis, antioxidant defense, and DNA repair. Zinc deficiency is associated with cognitive impairment, depression, and brain fog. Clinical studies show zinc supplementation can improve cognitive function, attention, and memory, particularly in those with insufficient zinc status.
Zinc is scientifically recognized as a critical micronutrient for wound healing, including burns. It plays essential roles in cellular proliferation, immune function, and collagen synthesis. Zinc deficiency is associated with delayed wound healing; supplementation improves outcomes in deficient individuals. Topical zinc formulations (zinc oxide) have traditional and clinical use for burn wound care.
Zinc supplementation is supported by a 2021 systematic review (PubMed PMID 34146924; 7 clinical trials, n=482 RAS patients) in which 5 of 7 trials showed significantly better efficacy of zinc in reducing RAS recurrence rates versus controls. A double-blind RCT (PMC7385976; n=46 RAS patients) of topical zinc sulfate mucoadhesive tablets found significant reductions in lesion diameter (days 3, 5, 7; p=0.001) and pain (from day 4; p=0.001) versus placebo.
Zinc is an essential trace mineral required for chondrocyte proliferation and survival, collagen metalloenzyme activity, and tissue inhibitors of metalloproteinases (TIMPs) preventing excessive cartilage degradation. Synovial fluid zinc concentrations are significantly reduced in OA patients. Low serum zinc correlates inversely with OA severity and elevated cartilage degradation biomarkers in clinical studies. Zinc is a standard component of validated combination joint supplement formulas.
Zinc deficiency is consistently documented in newly diagnosed celiac disease patients and may persist on long-term gluten-free diet, as confirmed by multiple systematic reviews and the ACG 2013 guidelines. A 2025 Scientific Reports study confirmed significantly lower zinc levels in 59 newly diagnosed CeD patients vs. controls. The ACG 2013 guidelines recommend zinc screening and supplementation at CeD diagnosis.
Zinc's immunomodulatory and antioxidant properties are relevant to HPV clearance and cervical dysplasia prevention. The 2023 MDPI micronutrients review identified zinc as having a potential protective role in the natural history of HPV infection and CIN. A 2025 meta-analysis attributed zinc supplementation to better HPV clearance and lesion regression. Evidence is primarily observational and mechanistic; dedicated RCTs for zinc alone in CIN are limited.
Zinc supports the immune system and has anti-inflammatory effects. Studies in asthmatic children found zinc deficiency correlated with more severe airway obstruction (reduced FEV1 and FEV1/FVC). Zinc deficiency has been associated with increased allergic disease severity in children. A 2025 review in Children (MDPI) published as part of vitamin C and allergy research notes that all enrolled asthmatic pediatric patients had zinc deficiency, with plasma zinc positively correlated with lung function parameters.
Zinc is required for collagen matrix synthesis, osteoblast differentiation via Runx2 stimulation, and bone mineralization. A 2022 PMC study in prepubescent girls showed vitamin C and zinc intake were positively associated with bone structural measures. A 2023 PMC review confirmed zinc's significant role in normal bone tissue development and homeostasis.
Zinc is WHO-recommended for treating acute diarrhea in children under five as part of standard management alongside oral rehydration therapy. A 2024 systematic review and meta-analysis commissioned by WHO (38 RCTs) found zinc supplementation reduces diarrhea duration by approximately 13 hours and improves recovery rates in children with acute diarrhea. It is one of the most evidence-based micronutrients for children's digestive health.
Zinc is an essential micronutrient required for proper immune cell development and function in children. The WHO recommends zinc supplementation for children in high-burden regions, with clinical trials showing significant reductions in diarrheal disease and respiratory infection frequency and severity. Zinc supplementation can shorten common cold duration by approximately 33% and reduced hospital stays in pediatric pneumonia trials.
Zinc is an essential trace element for immune function, growth, and development with IOM-established RDAs for children. NIH ODS-funded label analysis found zinc in the 13 core nutrients at or above RDA in most children's MVMs. WHO and UNICEF recommend zinc supplementation for children with diarrhea or growth faltering.
Zinc is a cofactor for over 200 metalloenzymes involved in energy metabolism, DNA synthesis, and immune function. EFSA authorizes a health claim for zinc contributing to normal energy-yielding metabolism. The 2020 Tardy et al. review includes zinc among micronutrients with recognized roles in fatigue when status is inadequate.
Zinc has well-documented anti-inflammatory activity supported by multiple human clinical trials and meta-analyses. It inhibits NF-κB activation, suppresses pro-inflammatory cytokines (IL-6, TNF-α), and reduces oxidative stress markers such as CRP and MDA. Meta-analyses of RCTs confirm significant reductions in CRP and IL-6 with zinc supplementation in adults, though effect sizes vary by population, dose, and duration.
There is human and clinical evidence linking zinc status to cognitive health in aging. Zinc deficiency has been associated with increased dementia risk and poorer cognitive performance in observational and cohort studies, while a randomized controlled trial in older adults found modest benefits on spatial working memory with supplementation. The relationship is bidirectional and complex—both deficiency and dysregulated excess can impair brain function—and current evidence does not yet support supplementation as a treatment for established cognitive decline.
Zinc lozenges are among the best-studied supplements for common cold treatment. Multiple meta-analyses confirm that zinc acetate and gluconate lozenges containing >75 mg/day elemental zinc shorten cold duration in adults by approximately 33–37%. The NCCIH and AAFP both recognize zinc as an effective treatment for cold symptoms in adults. Benefits are dose- and formulation-dependent.
Topical zinc formulations (zinc oxide, zinc sulfate) have been evaluated in multiple RCTs and shown to modestly reduce the duration and severity of cold sore outbreaks. Zinc salts applied to herpes lesions decrease viral load and improve healing rates. Zinc gluconate is listed in the US Homeopathic Pharmacopoeia with an OTC indication for cold sores, and topical zinc oxide is referenced in authoritative cold sore treatment reviews.
Zinc deficiency occurs acutely after concussion and is associated with worse outcomes; its correction has improved TBI outcomes in human studies. It protects the blood-brain barrier by supporting metallothionein synthesis and has antioxidant/anti-excitotoxic properties. A 2017 PMC review rated zinc alongside magnesium as having class III clinical evidence for improving TBI outcomes. A 2024 review and 2022 Frontiers review both identified zinc as one of the evidence-supported minerals for mTBI recovery.
Zinc is a cofactor for over 300 enzymes including metalloproteinase inhibitors that protect connective tissue matrix, and also supports collagen synthesis by facilitating procollagen conversion alongside vitamin C and copper cofactors. It is required for fibroblast function, wound healing, and promotes bone tissue synthesis. Zinc deficiency is associated with impaired connective tissue repair.
Zinc deficiency is prevalent in COPD patients and contributes to impaired antioxidant defense and immune function. A PMC review lists zinc among micronutrients with protective roles against chronic lung disease. A 2024 meta-analysis includes zinc in complex micronutrient supplementation that improved FEV1 and FEV1/FVC in COPD patients.
Zinc deficiency is a well-documented complication of Crohn's disease, caused by chronic diarrhea, malabsorption, and extensive small bowel involvement. The Crohn's & Colitis Foundation and gastroenterology clinicians list zinc supplementation as an established nutritional intervention in CD. Low zinc levels are associated with impaired mucosal healing and immune dysfunction.
Zinc pyrithione is an FDA-approved OTC anti-dandruff active used for over 50 years and is the most widely used anti-dandruff compound globally. Case-control studies show significantly lower serum zinc in seborrheic dermatitis patients vs. healthy controls (p=0.045). Topically, zinc exerts antifungal activity against Malassezia and regulates sebum production. It is one of only five FDA-approved anti-dandruff actives in the United States.
Zinc is an essential trace element with consistent evidence linking deficiency to depression. Lower serum zinc is repeatedly found in depressed patients versus controls. Clinical trials show zinc supplementation reduces depressive symptoms as both monotherapy and adjunct to antidepressants, and dietary zinc intake is inversely associated with depression risk (RR 0.66).
Zinc has been studied in atopic dermatitis for its anti-inflammatory and barrier-supporting properties, and low serum zinc levels have been associated with AD severity. However, the AAD guidelines rate evidence as inconsistent for zinc supplementation in established AD. Topical zinc preparations (zinc oxide) are also used for irritant and diaper dermatitis.
Zinc oxide is the primary FDA-recognized OTC active ingredient for treating and preventing diaper rash. It functions as a physical barrier, repelling moisture away from skin while providing mild astringent and antiseptic effects. Concentrations of 10–40% are used clinically, with higher concentrations reserved for more severe cases.
Zinc supplementation is recommended by WHO for acute diarrhea management in children, supported by multiple systematic reviews and meta-analyses. A systematic review of 38 RCTs commissioned by WHO found zinc supplementation reduced diarrhea duration by approximately 13.27 hours and increased recovery rate (RR=1.07, moderate certainty). For persistent diarrhea, recovery RR was 1.75.
Zinc is critical for activating antioxidant enzymes, cellular repair of ocular surface cells, and modulating immune responses in DED. A clinical DED multivitamin study found oral zinc-containing supplements improved intractable dry eye. Topical zinc-hyaluronate improves DED symptoms by reducing corneal receptor excitability, confirmed in published clinical studies.
Zinc plays a role in immune regulation and skin barrier maintenance; deficiency is consistently associated with eczema. RCTs of oral zinc sulfate have been conducted in atopic dermatitis patients, and lower serum zinc levels are found in eczema patients compared to controls. Zinc supports epithelial integrity and modulates inflammatory responses.
Zinc is an essential trace element required as a cofactor for over 300 enzymes including lactate dehydrogenase and carbonic anhydrase, which are involved in cellular energy metabolism and pH regulation during exercise. EFSA authorizes the health claim that zinc contributes to normal energy-yielding metabolism. Deficiency causes fatigue and impaired physical performance.
Zinc is essential for testosterone biosynthesis and is recognized as a cofactor for enzymes involved in sexual function. Clinical evidence links zinc deficiency to hypogonadism and erectile dysfunction; zinc supplementation in deficient men restores testosterone and improves sexual function. A 2023 animal study (Redox Rep) mechanistically confirmed zinc improves erectile function by preventing penile oxidative injury and upregulating testosterone.
Zinc is the most abundant trace mineral in the retina and is required for the enzymatic activity of retinal dehydrogenase, which converts vitamin A to retinal for phototransduction. It is a component of the AREDS and AREDS2 formulas, where high-dose zinc (80 mg/day) reduced AMD progression risk by ~25% in a large NIH-sponsored multicenter RCT. Zinc supports retinal metabolism and the visual processing relevant to digital eye fatigue.
Zinc is the most extensively studied micronutrient for male fertility. Seminal zinc levels are significantly lower in infertile men, and a meta-analysis in Scientific Reports found zinc supplementation significantly improved semen volume, sperm motility, and normal morphology in infertile males. It plays direct roles in spermatogenesis, sperm chromatin stability, capacitation, and testosterone balance. A 2020 large NIH-funded RCT found no improvement in live birth rates with combined zinc+folic acid, indicating benefits may be specific to zinc-deficient men.
Zinc is essential for ovulation, follicular development, and oocyte maturation. Zinc deficiency impairs ovulation; co-supplementation studies (zinc with magnesium, calcium, vitamin D/E) show improvements in insulin sensitivity and hormonal profiles in PCOS. Zinc is included in international fertility nutrition recommendations.
Zinc (5 mg/day) was included in the FLIES RCT combination (n=61, 6 months) that significantly reduced floater visual discomfort and vitreous opacity areas versus placebo. It contributes antioxidant properties via superoxide dismutase and antiglycation activity relevant to vitreous collagen integrity.
Multiple RCTs and a systematic review have examined zinc supplementation in children with ADHD. A 12-week placebo-controlled trial in 400 children found zinc sulfate superior to placebo for hyperactivity, impulsivity, and socialization. Children with ADHD commonly have lower zinc levels linked to impaired neurotransmitter metabolism affecting attention.
Zinc has established antifungal properties and is a core component of FDA-approved topical antifungal formulations (zinc undecylenate). It supports immune defense against fungal infections and inhibits Candida morphogenesis in vitro. Zinc pyrithione is widely used in antifungal/anti-dandruff products targeting Malassezia. Zinc deficiency is associated with increased susceptibility to cutaneous fungal infections.
Zinc (particularly zinc carnosine) is well-documented for strengthening the gastric mucosal lining and accelerating gastric epithelial healing in gastritis. Zinc carnosine has demonstrated in clinical trials the ability to protect against gastric mucosal damage, inhibit H. pylori, and reduce gastric inflammation. Zinc is listed among proposed natural treatments for gastritis in authoritative databases.
Zinc is a trace mineral essential for retinal function, serving as a cofactor for antioxidant enzymes (superoxide dismutase) and retinol-binding protein, facilitating vitamin A transport to the retina. In the original AREDS trial (n=3,640), high-dose zinc (80 mg/day) combined with antioxidants reduced AMD progression risk by 25%. Zinc is a core component of the recommended AREDS and AREDS2 supplementation formulas.
Zinc is an essential trace element with antioxidant and neuroprotective functions relevant to glaucoma. It is a cofactor for superoxide dismutase in the retina and has been studied in glaucoma nutraceutical formulations. A 2018 systematic review listed zinc among trace elements with putative glaucoma-protective effects.
A 2022 animal study found zinc intervention reduced serum uric acid and downregulated xanthine oxidase and adenosine deaminase activities in hyperuricemic rats on a high-purine diet, while also favorably modifying gut microbiota. Zinc's role as a superoxide dismutase cofactor may provide secondary anti-inflammatory benefits relevant to gout.
Zinc has documented effects on the GH–IGF-1 axis. Clinical trials in prepubertal children show that zinc supplementation raises serum IGF-1 and IGFBP-3 levels. The effect is most pronounced in zinc-deficient populations and with doses ≤10 mg/day over more than 8 weeks. Zinc appears to act downstream of GH secretion, directly stimulating IGF-1 production rather than altering pituitary GH output.
Zinc is an antimicrobial and anti-inflammatory mineral used as zinc chloride and zinc oxide in toothpastes and mouthwashes with documented efficacy for reducing periodontal plaque and gingivitis. A systematic review of active ingredients for periodontal diseases (PMC8037529) includes zinc compounds among the major oral care active ingredients reviewed for antiplaque and anti-gingivitis properties.
Zinc deficiency is consistently associated with alopecia areata and telogen effluvium, with lower serum zinc levels found in multiple patient cohorts. Zinc contributes to protein synthesis, 5-alpha-reductase inhibition, and cell proliferation in hair follicles. Evidence for supplementation is strongest in documented deficiency states; supplementation in zinc-sufficient individuals lacks robust support.
Zinc is a critical cofactor for enzymes in the hair follicle and acts as an inhibitor of follicle apoptosis. Zinc deficiency is associated with hair loss, and a 2025 systematic review linked deficiencies in zinc—among other micronutrients—to androgenetic alopecia progression. Cross-sectional studies show elevated prevalence of zinc deficiency in patients with telogen effluvium.
Zinc is an essential trace mineral for immune function, DNA repair, antioxidant defense (SOD), and over 300 enzymes. Zinc deficiency is prevalent in older adults and directly linked to immune senescence, increased oxidative stress, impaired DNA damage repair, and accelerated aging. Supplementation in deficient older adults restores immune function and reduces inflammatory markers.
Zinc is a trace mineral with the most conclusive evidence linking intake to child growth among all micronutrients. It promotes immunity, resistance to infection, and proper growth and development of the nervous system. The CDC, WHO, and IOM all identify zinc as critical for healthy growth; meta-analyses of zinc supplementation trials in children demonstrate significant improvements in linear growth and weight gain, particularly in zinc-deficient populations.
Zinc is the most abundant trace mineral in the eye, found at highest concentrations in the retinal pigment epithelium and choroid. It is a critical cofactor for antioxidant enzymes and plays a role in vitamin A metabolism in the retina. The AREDS1 trial demonstrated that high-dose zinc (80 mg/day) combined with antioxidants reduced AMD progression risk by ~25%.
Zinc deficiency is associated with tinnitus and increased hearing loss risk. Zinc is essential for immune function and inner-ear tissue maintenance, and zinc supplementation has been studied in tinnitus patients with low serum zinc levels showing some clinical improvement. Multiple reviews identify zinc as having a clinically favorable effect on tinnitus intensity, particularly in zinc-deficient patients.
Multiple clinical and epidemiological studies establish a meaningful link between zinc status and cardiovascular health. Low serum zinc is consistently associated with increased risk of coronary artery disease, heart failure, and adverse cardiac events. Zinc supplementation has been shown in meta-analyses of RCTs to improve key CVD risk factors — notably triglycerides, total cholesterol, and glycemic indices — though effects on blood pressure are inconsistent. The relationship is dose- and duration-dependent, with low-dose, long-duration supplementation appearing most beneficial.
Zinc is an essential trace mineral that induces metallothionein synthesis, a key endogenous metal-binding protein that sequesters cadmium and protects against lead toxicity. It also competes with cadmium and lead for intestinal absorption. A PubMed study (2023) confirmed zinc and selenium alleviated hepatotoxicity from a heavy metal mixture in animal models.
Topically applied zinc salts directly inactivate clinical isolates of HSV-1 and HSV-2 in vitro and have shown efficacy in reducing outbreak duration and severity in multiple human trials. A randomized double-blind placebo-controlled trial of 0.05% topical zinc sulfate demonstrated significant superiority over placebo for recurrent HSV. Long-term topical zinc application may reduce or eliminate recurrent genital herpes episodes.
Zinc acts as a cofactor supporting the liver's betaine-homocysteine methyltransferase (BHMT) enzyme system that remethylates homocysteine to methionine. The Food For The Brain Foundation specifically identifies zinc as supporting the conversion of homocysteine in the liver via SAMe generation. Low zinc status has been associated with elevated homocysteine in observational studies.
Zinc is required for adrenal steroidogenesis and serves as a cortisol modulator; deficiency is associated with elevated cortisol and HPA axis dysregulation. The 2025 American Journal of Medicine review identifies zinc deficiency as impairing adrenal and neuroendocrine function, and clinical evidence shows supplementation modulates ACTH/cortisol while supporting DHEA production.
Zinc is required for thyroid hormone production, TSH synthesis, and the deiodinase-mediated conversion of T4 to active T3. Low zinc concentrations are associated with hypothyroidism, and a 2015 RCT showed that zinc supplementation (alone or with selenium) significantly increased free T3 and improved thyroid function in hypothyroid patients. Studies typically use 25–30 mg/day.
Zinc deficiency is highly prevalent in IBD, affecting approximately one-third of the overall IBD population and up to 45% in some cohorts. Deficiency is most common in Crohn's disease due to impaired small-intestinal absorption. Zinc exerts anti-inflammatory effects via NF-κB inhibition, supports intestinal epithelial repair, and modulates the gut microbiota. Clinical trial evidence for supplementation remains preliminary but supports correcting deficiency to improve disease severity.
Zinc is a trace mineral that plays a regulatory role in melatonin metabolism and sleep-wake cycle regulation. RCTs support its use for improving sleep quality in populations with sleep disturbances including shift workers and older adults.
Zinc is essential for insulin synthesis, storage, secretion, and signal transduction at the insulin receptor. Multiple clinical trials and meta-analyses confirm zinc supplementation reduces fasting blood glucose, HbA1c, and HOMA-IR in T2DM and PCOS patients. A 2024 RCT combining gymnema, inositols, alpha-lactalbumin, and zinc demonstrated improved glycemic and lipid profiles in T2DM.
Zinc is associated with urinary mineral balance relevant to kidney stone risk. Zinc inhibits calcium oxalate crystallization in vitro, and low urinary zinc is associated with increased calcium oxalate stone risk. NHANES epidemiological data show dietary zinc intake is inversely associated with kidney stone prevalence. It has been studied as part of urinary antioxidant parameters in stone formers.
Zinc supports intestinal tight junction integrity and immune function. A 2025 patient-based clinical study (PMC12429388) showed that orally administered zinc gluconate (26 mg twice daily) induced tight junctional remodeling and reduced passive transmucosal permeability in human intestinal mucosa. Zinc has a centuries-long history as a clinical treatment for diarrhea and gastrointestinal conditions, and numerous cell culture and animal model studies confirm its barrier-protective role.
Multiple studies, including a double-blind RCT in 51 postmenopausal women (50 mg/day zinc for 8 weeks), found inverse correlations between zinc intake/plasma zinc and serum leptin. A PMC review concluded there is a positive correlation between zinc and leptin regulation. Zinc deficiency has been associated with disrupted leptin-mediated appetite signaling.
Zinc is an essential trace mineral with a well-established role in testosterone synthesis and male reproductive function. Clinical studies confirm that zinc deficiency is directly associated with hypogonadism and low libido in men, and supplementation restores testosterone levels and sexual function in deficient individuals. It is listed among the most common ingredients in men's sexual health supplements with documented activity.
Zinc is an essential mineral required for hepatic alcohol metabolism enzymes (alcohol dehydrogenase, aldehyde dehydrogenase), phase II detoxification enzyme metallothionein induction, and liver regeneration. Zinc deficiency is common in alcoholic liver disease and cirrhosis. Clinical studies demonstrate zinc supplementation improves liver enzyme levels, reduces oxidative stress, and supports liver regeneration in chronic liver disease patients.
Zinc is the most abundant trace mineral in the eye and is concentrated in the RPE-choroid layer. It is an essential cofactor for over 200 enzymes, including retinal dehydrogenase, and constitutes the AREDS formula core ingredient. AREDS demonstrated that zinc alone (80 mg/day) produced a statistically significant ~25% reduction in AMD progression risk. It remains the only mineral with this level of evidence and is included in both AREDS and AREDS2 formulations.
Zinc is a cofactor for 5α-reductase and enzymes involved in hair follicle cycling and keratin synthesis. A 2024 systematic review (PubMed 39440586, 49 studies) found zinc deficiency consistently associated with increased AGA risk, with supplementation showing potential benefit. A 2014 Journal of Drugs in Dermatology review identifies zinc among the best-evidenced supplemental treatments for AGA.
Zinc is an essential cofactor for diamine oxidase (DAO) synthesis and activity, the primary histamine-degrading enzyme. Deficiency reduces DAO activity and increases histamine accumulation relevant to MCAS. Zinc also has direct anti-inflammatory effects via NF-κB inhibition and reduction of pro-inflammatory cytokines involved in mast cell-mediated inflammation.
A 2024 systematic review and meta-analysis of RCTs confirmed zinc supplementation significantly reduces pain severity in primary dysmenorrhea. Zinc inhibits prostaglandin production, upregulates superoxide dismutase 1, and improves endometrial microcirculation. Lower zinc levels have been observed in women with PMS and dysmenorrhea.
Zinc is essential for neurotransmitter synthesis, synaptic function, and cognitive performance. EU health claims recognize its contribution to normal cognitive function and protection from oxidative stress. Zinc deficiency impairs mental alertness and supplementation in deficient individuals improves cognition.
Multiple clinical trials and meta-analyses demonstrate that zinc plays a measurable role in metabolic syndrome (MetS), acting on insulin signaling, glycemic control, lipid profiles, and oxidative stress. A 2022 meta-analysis of 13 observational studies (18,073 participants) found higher dietary zinc intake was inversely associated with MetS risk (RR=0.75). Intervention trials show zinc supplementation can improve fasting glucose, insulin resistance (HOMA-IR), and lipid parameters, though effect sizes vary and findings remain somewhat inconsistent across populations.
Zinc is an essential trace element with well-documented roles in carbohydrate, lipid, and protein metabolism, functioning as a cofactor for over 300 metalloenzymes. It is critically involved in insulin synthesis, storage, and release, making it central to glucose homeostasis. Multiple randomized controlled trials demonstrate that zinc supplementation can improve insulin resistance, fasting glucose, and inflammatory markers in populations with metabolic dysfunction.
Zinc is a structural cofactor for DNA methyltransferases (DNMTs), enzymes that execute cytosine methylation. It is also required for BHMT (betaine-homocysteine methyltransferase) function in the BHMT methylation pathway. A 2022 PMC systematic review (PMC9530842) reviews multiple studies confirming the association between zinc levels and DNA methylation status.
Zinc is a structural and catalytic component of mitochondrial enzymes including copper-zinc superoxide dismutase (CuZnSOD), which protects mitochondria from oxidative damage. It also supports mitochondrial membrane integrity and is included in the scientific literature as a micronutrient required for optimal mitochondrial function.
Zinc supplementation has shown benefit for muscle cramps in cirrhotic patients with documented low serum zinc, based on small observational studies. A systematic review of cramp treatments in cirrhosis concluded zinc was safe and showed beneficial effects on muscle cramps. Evidence is limited to disease-state-associated cramps and small, non-randomized studies.
Zinc is an essential cofactor for Cu/Zn-superoxide dismutase (antioxidant defense in skeletal muscle), protein synthesis, and IGF-1 signaling. Deficiency impairs recovery, muscle repair, immune function, and testosterone production; athlete populations frequently have suboptimal zinc status due to exercise-related losses.
Zinc is essential for keratin synthesis and cell division in the nail matrix; zinc deficiency causes nail dystrophy, brittleness, Beau's lines, and slow growth (Cleveland Clinic; Indian J Dermatol Venereol Leprol 2012). Supplementation of 20–30 mg/day corrects nail fragility in deficient individuals according to multiple clinical reviews. PMC 10987172 and PMC 11961095 both document this deficiency-correction benefit.
Zinc is an essential trace mineral required for nerve tissue antioxidant defense (Cu/Zn-SOD), nerve growth factor signaling, myelin maintenance, and the delta-6-desaturase enzyme that converts linoleic acid to neuroprotective GLA. Zinc deficiency is a recognized cause of peripheral neuropathy, and lower zinc levels are found in diabetic patients with more severe neuropathy.
Zinc is an essential trace mineral required as a cofactor in GABA-synthesizing enzyme (GAD), tryptophan hydroxylase, and monoamine oxidase. Meta-analyses document significantly lower serum zinc in depressed patients. RCTs show zinc augmentation of antidepressant therapy improves treatment outcomes, consistent with neurotransmitter synthesis support.
Zinc is concentrated in the retinal pigment epithelium and photoreceptors, where it serves as a cofactor for retinol dehydrogenase, the enzyme that converts retinol to retinal in the visual cycle. Zinc deficiency in humans causes abnormal dark adaptation and night blindness, typically reversible with supplementation. Zinc potentiates vitamin A's effect on restoring night vision in deficient individuals.
Zinc plays a critical role in bone matrix synthesis and osteoblast function. Low zinc status is associated with reduced bone density and increased osteoporosis risk. It is listed among the essential minerals for osteoporosis prevention by major nutritional authorities, and supplementation studies demonstrate improved bone formation markers.
Women with PCOS frequently have zinc deficiency, which correlates with insulin resistance severity. Multiple RCTs show zinc supplementation (4–50mg/day for 8–12 weeks) improves HOMA-IR, lipid profiles, and androgen markers. Systematic reviews confirm benefits when used alone or in combination with other micronutrients.
Zinc is one of the most commonly deficient nutrients in picky eaters who avoid meat, seafood, and legumes. Zinc deficiency impairs taste perception and appetite, potentially worsening selective eating. A randomized controlled trial of 10 mg/day zinc for 12 weeks in preschool children improved caloric intake and appetite scores.
Zinc supplementation (20 mg/day) has been shown in clinical evidence to accelerate recovery from severe pneumonia in children. Multiple systematic reviews support zinc's role in reducing pneumonia and respiratory tract infection incidence, particularly in elderly and children. Evidence is mixed for hospitalized severe pediatric pneumonia, but strongly supportive for community-based pneumonia prevention.
Zinc is essential for immune cell differentiation and function and has been shown in meta-analyses to shorten the duration of common cold by approximately 33% when taken within 24 hours of symptom onset. It is a core nutrient for post-illness immune restoration, with deficiency impairing recovery.
Zinc supports immune defense in the upper respiratory mucosa and has been used in clinical nutraceutical formulations that significantly reduced nasal symptoms including rhinorrhea in upper respiratory tract infections. A single-blinded clinical trial (Healthcare, 2022) found a supplement containing Boswellia, bromelain, zinc, and magnesium improved nasal findings and reduced infection duration. Zinc also inhibits rhinoviral replication, a common cause of post-nasal drip.
Zinc is critical for wound healing through its roles in DNA synthesis, cell proliferation, collagen formation, and immune function. Perioperative zinc supplementation combined with arginine and vitamin C significantly augmented collagen synthesis in a RCT of hernia repair patients. Zinc deficiency is associated with impaired wound healing and increased surgical infection risk.
Zinc is essential for immune cell function and antiviral defense, and clinical data show 50 mg/day elemental zinc reduces CRP in post-viral inflammatory states. Studies have found zinc deficiency common in long COVID patients. A 2024 PubMed review identified zinc among the most promising trace elements for COVID-19 rehabilitation, with clinical trials confirming reduced viral load with supplementation.
Zinc serum levels decrease significantly after vaginal delivery, impairing wound healing, collagen synthesis, and immune defense. A 2022 PMC study (n=197 postpartum cesarean women) found zinc supplementation significantly reduced postpartum depression risk (adjusted OR 0.249). Zinc is consistently identified by NIH ODS and clinical postnatal guidelines as a critical postpartum nutrient for tissue repair and mood.
Zinc is critical for cell division, immune function, and fetal growth; deficiency is associated with intrauterine growth restriction, preterm birth, and congenital malformations. NIH ODS lists zinc among nutrients with critical prenatal roles that are underconsumed. A Cochrane systematic review of zinc supplementation in pregnancy found significant reductions in preterm birth (RR 0.86). RDA increases to 11 mg/day during pregnancy.
Zinc is required for LH synthesis in the pituitary and for progesterone production in corpus luteum granulosa cells. Zinc deficiency has been associated with luteal phase defects and anovulation. It also plays a role in regulating the estrogen-to-progesterone ratio. Clinical evidence and mechanistic studies establish zinc as a cofactor necessary for folliculogenesis, ovulation, and luteal steroidogenesis. Supplementation at 15–25 mg/day is used clinically to support progesterone production.
Zinc is essential for prostate health; the healthy prostate accumulates the highest concentration of zinc of any tissue in the body. Studies show that BPH and prostate cancer tissue have significantly lower zinc levels than normal tissue. Zinc regulates zinc transporters (ZIP1) and supports apoptosis in prostate cells. Evidence for supplementation reducing cancer risk in adequate men is not established.
The prostate gland accumulates the highest zinc concentration of any soft tissue, and zinc levels are markedly reduced in BPH and prostate cancer tissues. Zinc regulates 5α-reductase activity and promotes apoptosis of prostate epithelial cells. A 2019 BPH nutraceutical review cites zinc as capable of producing similar benefits to lycopene on BPH symptoms; zinc is included in recognized BPH phytotherapy formulations alongside beta-sitosterol and selenium.
Lower serum zinc levels have been significantly correlated with RLS severity, particularly in pregnant women. A study found zinc and magnesium levels in pregnant RLS patients were significantly lower than in controls, with an inverse correlation between serum zinc and symptom severity.
Zinc is an essential trace mineral involved in immune regulation and antioxidant defense. It is listed among proposed natural treatments for RA by the EBSCO Research Starters and Arthritis Foundation. Some clinical studies show reduced RA disease activity markers with zinc supplementation, consistent with its role in modulating immune cell function.
A double-blind, placebo-controlled trial (Sharquie et al., Int J Dermatol 2006) showed oral zinc sulfate significantly improved rosacea severity scores after 3 months. Topical 5% zinc sulfate reduced acne rosacea severity with 40% moderate and 60% good responses. Zinc exerts anti-inflammatory and antimicrobial effects relevant to Demodex-associated rosacea.
Zinc plays essential roles in wound healing and scar tissue formation through enzymatic cofactor functions in collagen synthesis, DNA repair, and immune regulation. Zinc deficiency impairs wound healing and scar quality; supplementation supports optimal collagen cross-linking and scar outcomes.
Zinc is a structural cofactor for alkaline phosphatase, which deposits hydroxyapatite during bone formation, and is required for osteoblast development and collagen production. Studies link zinc deficiency in AIS patients to delayed bone development and reduced peak bone density. It is also cited in context of abnormal trace element levels in idiopathic scoliosis patients.
Zinc has immunomodulatory properties with evidence for reducing allergic responses in an allergic rhinitis mouse model through p38 MAPK pathway modulation (J Trace Elements Med Biol, 2023). It was also included in an RDBPCT-tested multicomponent supplement (quercetin phytosome + zinc + vitamin C) for seasonal AR in children with favorable results.
Zinc lozenges and nasal gels have clinical evidence for shortening the duration of colds that precede sinusitis, and zinc supplementation may reduce the likelihood of sinusitis developing from viral URTIs. Multiple studies confirm zinc reduces cold symptom intensity and duration, and several authoritative sinusitis treatment resources include zinc as a supportive supplement.
Zinc is an essential mineral required as a cofactor for collagen-synthesizing enzymes (prolyl hydroxylase) and antioxidant superoxide dismutase. Zinc deficiency significantly impairs skin structure, collagen synthesis, and wound healing, accelerating skin aging. Authoritative nutritional dermatology sources confirm zinc as critical to collagen formation and skin quality in the aging context.
Zinc is a cofactor for enzymes involved in collagen synthesis and MMP regulation. In a 12-week RCT, a combination of collagen peptides with zinc (3 mg), vitamin C, vitamin E, and biotin significantly improved skin elasticity, hydration, roughness, and density in 72 healthy women versus placebo. Zinc deficiency impairs wound healing and collagen biosynthesis.
Zinc has meta-analytic evidence for reducing cold symptom severity including sore throat. A BMC Family Practice meta-analysis (Hemilä & Chalker, 2015) found high-dose zinc acetate lozenges significantly reduced duration of cold symptoms. A systematic review and meta-analysis (PubMed, 2024) also supported zinc supplementation for prevention of post-operative sore throat. Zinc lozenges work by direct contact with throat tissue.
Zinc deficiency is consistently linked to reduced testosterone levels in men, and supplementation in zinc-deficient individuals has been shown to restore testosterone to normal levels. Zinc plays essential roles in LH receptor function and testosterone biosynthesis in Leydig cells. Multiple systematic reviews confirm zinc's role in supporting testosterone, particularly in deficient populations.
Zinc plays a key regulatory role in thyroid hormone metabolism by modulating deiodinase enzyme activity, TRH and TSH synthesis, and thyroid hormone receptor binding. Clinical studies show zinc supplementation improves FT3 and FT4 levels in zinc-deficient hypothyroid patients. Zinc transporters are expressed in the hypothalamus, pituitary, and thyroid gland.
Zinc has a documented role in cochlear physiology and synaptic transmission in the auditory system. Zinc deficiency has been reported in 2–69% of tinnitus patients across studies. A 2016 Cochrane systematic review of three RCTs (n=209) found no statistically significant evidence that oral zinc supplementation improves tinnitus symptoms, though a mechanistic rationale exists.
Zinc has direct RCT evidence in tonsillopharyngitis treatment. An open-label RCT (n=130 children) using a honey-propolis-Pelargonium-zinc supplement showed significantly lower tonsillitis severity scores vs. standard care alone. Zinc lozenges reduce pharyngeal infection severity and duration. Clinical guidelines reference zinc as a plausible adjunct for tonsillar immune support.
Zinc is incorporated into hydroxyapatite toothpaste formulations and has been shown to enhance enamel and dentin remineralization in vitro, particularly as zinc carbonate-hydroxyapatite. Zinc also inhibits cariogenic bacteria and reduces demineralization by integrating into the hydroxyapatite crystal lattice, increasing acid resistance.
Zinc, particularly as zinc-carnosine (polaprezinc), has demonstrated mucosal protective and antiulcer effects in clinical studies. It reduces inflammation, neutralizes free radicals, prevents intestinal cell death, and protects tight junctions between mucosal cells. Life Extension and EBSCO Research Starters list zinc among proposed natural treatments for ulcers.
Zinc lozenges are among the best-evidenced interventions for reducing common cold duration. NCCIH and a 2015 meta-analysis (3 RCTs, 80–92 mg/day zinc acetate) confirm significant reductions in nasal discharge (34%), nasal congestion (37%), cough (46%), and hoarseness (43%). Zinc lozenges should be started within 24 hours of symptom onset.
Zinc is accumulated in uniquely high concentrations in healthy prostate tissue and is depleted in BPH and prostate cancer. Epidemiological and laboratory studies associate lower zinc status with BPH progression, and supplemental zinc has been found in clinical practice to improve urine flow and reduce residual volume in men with BPH, though large rigorous placebo-controlled trials on zinc supplementation alone for urinary flow are limited.
Zinc is an essential immunomodulatory mineral with well-documented antiviral activity. It supports innate and adaptive immune cell function, enhances interferon signaling against RNA viruses, inhibits viral RNA-dependent RNA polymerase activity, and reduces cold duration by approximately 33% when taken within 24 hours of symptom onset.
Zinc is an essential cofactor for melanogenic metalloenzymes and has antioxidant properties relevant to vitiligo. Meta-analyses confirm significantly lower serum zinc in vitiligo patients. Adjuvant zinc supplementation alongside corticosteroids showed trends toward improved repigmentation, and zinc is included in recommended antioxidant protocols for vitiligo by expert dermatologists.
Multiple randomized controlled trials and a 16-study systematic review confirm oral zinc sulfate, intralesional zinc, and topical zinc are effective for viral warts. A landmark placebo-controlled RCT achieved 86.9% complete clearance in recalcitrant wart patients treated with oral zinc sulfate 10 mg/kg/day. Zinc acts primarily as an immunomodulator via Toll-like receptor-mediated dendritic cell regulation.
Zinc is one of the best-established micronutrients in wound healing, essential for DNA replication in dividing repair cells, collagen synthesis, immune function, and epithelialization. Multiple RCTs confirm zinc supplementation improves wound healing in deficient patients, and topical zinc is an approved wound treatment.
Zinc oxide is a primary active ingredient in calamine lotion, one of the most widely used and traditionally recognized treatments for insect bites and stings, providing soothing, antipruritic, and mild antiseptic effects. Zinc-containing formulations have long been standard first-aid recommendations for bite-related itching and skin irritation.
Body systems that Zinc may help support.
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