Zinc vitamin side effects



Table of Contents > Supplements > Zinc

Overview Dietary Sources Available Forms How to Take It Precautions Possible Interactions Supporting Research

Zinc is an essential trace mineral, so you get it through the foods you eat. Next to iron, zinc is the most common mineral in the body and is found in every cell. It has been used since ancient times to help heal wounds and plays an important role in the immune system, reproduction, growth, taste, vision, and smell, blood clotting, and proper insulin and thyroid function.

Zinc also has antioxidant properties, meaning it helps protect cells in the body from damage caused by free radicals. Free radicals may contribute to the aging process, as well as the development of a number of health problems, including heart disease and cancer. Antioxidants can neutralize free radicals and may reduce or even help prevent some of the damage they cause.

Your body doesn’t need a large amount of zinc. The recommended daily allowance for adults is 8 – 11 mg. It’s common to have slightly low levels of zinc, but taking a multivitamin, plus eating a healthy diet, should give you all the zinc you need.

It’s rare for people in industrialized countries to be seriously deficient in zinc. Low zinc levels are sometimes seen in the elderly, alcoholics, people with anorexia, and people on very restricted diets. People who have malabsorption syndromes, such as Crohn’s disease or celiac disease, may also be deficient in zinc.

Symptoms of zinc deficiency include loss of appetite; poor growth; weight loss; lack of taste or smell; poor wound healing; skin problems such as acne, atopic dermatitis and psoriasis; hair loss; lack of menstrual period; night blindness; white spots on the fingernails; and depression.

Zinc reduces the amount of copper your body absorbs, and high doses of zinc can cause a copper deficiency. For that reason, many doctors recommend that you take 2 mg of copper along with a zinc supplement.


Some studies suggest that taking oral zinc supplements may help improve acne. However, most studies used a high dose of zinc that could have toxic effects, and not all studies found any benefit. There is some evidence that a topical form of zinc, used along with the topical antibiotic erythromycin, might be helpful.

Age-Related Macular Degeneration(AMD)

Doctors often recommend zinc to slow the progress of AMD, an eye disease that occurs when the part of the retina that is responsible for central vision starts to deteriorate. A major clinical trial, the Age Related Eye Disease Study (AREDS1), found that people who had macular degeneration could slow down the damage by taking zinc (80 mg), vitamin C (500 mg), vitamin E (400 mg), beta-carotene (15 mg), and copper (2 mg). If you have macular degeneration, ask your doctor whether these vitamins and minerals might help you. This is a very large amount of zinc and should only be used under a doctor’s supervision.

A new study, AREDS2, is examining exactly what role zinc plays in macular degeneration.


Many people believe that taking zinc lozenges or using zinc nasal spray when they first show signs of a cold can reduce the duration and severity of symptoms. Not all studies agree, but most suggest that zinc acetate or gluconate lozenges may help you get over a cold faster. In one study, people who had early symptoms of a cold took either a lozenge with 13.3 mg of zinc gluconate or placebo. Those who took the zinc saw symptoms, such as coughing, runny nose, and sore throat, disappear faster than those who took placebo. But researchers aren’t sure what type of zinc works best for colds and whether flavorings added to the lozenges might affect how they work.

Zinc nasal sprays are controversial. Some studies have found zinc nasal sprays may help reduce cold symptoms, but other studies have found no effect. In addition, zinc nasal sprays may cause some people to lose their sense of smell. To be safe, talk to your doctor before using a zinc nasal spray.

There is some evidence that zinc supplements (not lozenges) may help lower the risk of getting a cold in the first place. In one study, elderly people in a nursing home who had normal levels of zinc had a lower risk of pneumonia, fewer new antibiotic prescriptions and fewer days of antibiotic use. More and better studies are needed that examine which kinds of zinc may be effective and against which kinds of cold viruses.

Sickle Cell Disease

People who have sickle cell disease are often deficient in zinc. Studies suggest that taking zinc supplements may help reduce symptoms of the disease. Children who took zinc showed improvements in height and weight, and had fewer sickle-cell crises.

Stomach Ulcers

Some studies suggest that zinc may help speed the healing of stomach ulcers. The studies used a form of zinc not available in the U.S.

Attention Deficit Hyperactivity Disorder (ADHD)

For children who have low levels of zinc, some evidence suggests that taking zinc may cause a slight improvement in symptoms, reducing hyperactivity, impulsivity, and impaired socialization in children. However, there was no change in attention deficit symptoms. Zinc may be most helpful to children with a high body mass index, low levels of free fatty acids in their blood, and low levels of zinc.

Herpes simplex (Cold Sores)

Cold sores are caused by the herpes simplex virus. In one study, people with cold sores used either a zinc oxide cream or placebo every 2 hours until their cold sores got better. Those who used the zinc cream had fewer symptoms and got better faster.


It’s common for people with HIV or AIDS to have low levels of zinc, even before symptoms appear. In people with AIDS, low levels of zinc may be a result of poor absorption, medications, and loss of this important nutrient through vomiting or diarrhea. Low levels of zinc can make the body more susceptible to infection, called an opportunistic infection. Some studies show that HIV positive people who take zinc have fewer infections, gain more weight, and have a better immune system response. But not all studies agree, and one even suggests that taking zinc may be associated with higher death rates. If you have HIV or AIDS, talk to your doctor before taking zinc or any supplement.

Wilson’s Disease

Preliminary evidence suggests that zinc may help treat Wilson’s disease, a condition which causes copper to build up in the body. Because zinc reduces how much copper the body absorbs, it may help reduce levels of copper in people with Wilson’s disease.


Other conditions may increase the need for zinc or affect how your body absorbs or uses this mineral. Researchers don’t know, however, whether taking zinc will help treat any of these conditions:

  • Acrodermatitis enteropathica (a skin disorder due to an inherited inability to absorb zinc properly)
  • Alcoholism
  • Cirrhosis (liver disease)
  • Kidney disease
  • Celiac disease
  • Inflammatory bowel disease (ulcerative colitis and Crohn’s disease)

Dietary Sources

Your body absorbs 20 – 40% of the zinc present in food. Zinc from animal foods like red meat, fish, and poultry is more readily absorbed by the body than zinc from plant foods. Zinc is best absorbed when taken with a meal that contains protein.

Available Forms

Zinc is available in several forms. Zinc sulfate is the least expensive form, but it is the least easily absorbed and may cause stomach upset.

More easily absorbed forms of zinc are zinc picolinate, zinc citrate, zinc acetate, zinc glycerate, and zinc monomethionine. If zinc sulfate causes stomach irritation, you can try another form, such as zinc citrate.

The amount of elemental zinc is listed on the product label (usually 30 – 50 mg). To determine the amount to take in supplement form, remember that you get about 10 – 15 mg from food.

Zinc lozenges, used for treating colds, are available in most drug stores. There are also nasal sprays developed to reduce nasal and sinus congestion, although they may have some safety issues (see “Precautions”).

How to Take It

You should take zinc with water or juice. If zinc causes stomach upset, it can be taken with meals. Don’t take zinc at the same time as iron or calcium supplements.

A strong relationship exists between zinc and copper. Too much of one can cause a deficiency in the other. If you take zinc, including zinc in a multivitamin, you should also take copper.

Do not give zinc supplements to a child without talking to your doctor.

Daily intake of dietary zinc (according to the National Academy of Sciences) are listed below:



You should not take high doses of zinc for more than a few days unless your doctor tells you to. Talk to your doctor before taking more than 40 mg of zinc per day and take breaks from zinc supplementation. During those breaks, get zinc from a well-balanced diet.


Because of the potential for side effects and interactions with medications, you should take dietary supplements only under the supervision of a knowledgeable health care provider.

Research has shown that less than 40 mg a day is a safe amount to take over time, but researchers are not sure what happens if more is taken over a long period. Additional concerns have been raised about combining multivitamins and additional zinc supplements and an increased risk of dying from prostate cancer. Speak with physician.

Taking 100 mg of zinc daily, or taking supplemental zinc for 10 years or longer, has been linked with a doubling of the risk developing prostate cancer in men.

Common side effects of zinc include stomach upset, nausea, vomiting, and a metallic taste in the mouth. High doses of zinc can cause dizziness, headache, drowsiness, increased sweating, loss of muscle coordination, alcohol intolerance, hallucinations, and anemia.

There are reports that a single dose of zinc as high as 10-30 grams can be lethal.

Very high doses of zinc may actually weaken immune function. High doses of zinc may also lower HDL (“good”) cholesterol and raise LDL (“bad”) cholesterol.

Some people who have used certain zinc nasal sprays to treat a cold have lost their sense of smell. Talk to your doctor before using a zinc nasal spray.

Possible Interactions

If you are being treated with any of the following medications, you should not use zinc without first talking to your health care provider.

Amiloride (Midamor) — Amiloride is a potassium-sparing diuretic (water pill) that may increase the levels of zinc in your blood. Do not take zinc supplements if you take amiloride.

Blood pressure medications, ACE Inhibitors — A class of medications called ACE inhibitors, used to treat high blood pressure, may decrease the levels of zinc in your blood. ACE inhibitors include:

Antibiotics — Zinc may decrease your body’s absorption of two kinds of antibiotics, quinolones and tetracyclines. These include:

  • Ciprofloxacin (Cipro)
  • Gatifloxacin (Tequin)
  • Levofloxacin (Levaquin)
  • Moxifloxacin (Avelox)
  • Norfloxacin (Noroxin)
  • Ofloxacin (Floxin)
  • Demeclocycline (Declomycin)
  • Minocycline (Minocin)
  • Tetracycline

However, doxycycline (Vibramycin) does not seem to interact with zinc.

Cisplatin (Platinol-AQ) — This drug, used for chemotherapy to treat some types of cancers, may cause more zinc to be lost in your urine. If you are undergoing chemotherapy, do not take zinc or any other supplement without talking to your oncologist.

Deferoxamine (Desferal) — This medication, used to remove excess iron from the blood, also increases the amount of zinc that is lost in urine.

Immunosuppressant medications — Since zinc may make the immune system stronger, it should not be taken with corticosteroids (such as prednisone), cyclosporine, or other medications intended to suppress the immune system.

Penicillamine — This medication, used to treat Wilson’s disease (where excess copper builds up in the brain, liver, kidney, and eyes) and rheumatoid arthritis, decreases the levels of zinc in your blood.

Thiazide diuretics (water pills) — These medications lower the amount of zinc in your blood by increasing the amount of zinc that is passed in your urine. If you take thiazide diuretics, your doctor will monitor levels of zinc and other important minerals in your blood:

  • Chlorothiazide (Diuril)
  • Chlorthalidone (Hygroton)
  • Hydrochlorothiazide
  • Indapamide (Lozol)
  • Metolozone (Zaroxolyn)
  • Polythiazide (Renese)
  • Quinethazone (Hydromox)
  • Trichlormethiazide (Metahydrin, Naqua, Diurese)

Supporting Research

Age-Related Eye Disease Study Research Group. A randomized, placebo-controlled, clinical trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age-related macular degeneration and vision loss: AREDS report no. 8. ArchOphthalmol. 2001;119(10):1417-1436.

Al-Maroof RA, Al-Sharbatti SS. Serum zinc levels in diabetic patients and effect of zinc supplementation on glycemic control of type 2 diabetics. Saudi Med J. 2006 Mar;27(3):344-50

Altaf W, Perveen S, Rehman KU, et al. Zinc supplementation in oral rehydration solutions: experimental assessment and mechanisms of action. J Am Coll Nutr. 2002;21(1):26-32.

Anderson RA, Roussel AM, Zouari N, Mahjoub S, Matheau JM, Kerkeni A. Potential antioxidant effects of zinc and chromium supplementation in people with type 2 diabetes mellitus. J Am Coll Nutr. 2001;20(3):212-218.

Arnold LE, Pinkham SM, Votolato N. Does zinc moderate essential fatty acid and amphetamine treatment of attention deficit/hyperactivity disorder? J Child Adolesc Psychopharmacol. 2000;10:111-117.

Basnet S, et al. A randomized controlled trial of zinc as adjuvant therapy for severe pneumonia in young children. Pediatrics. 2012;129(4):701-8.

Belongia EA, Berg R, Liu K. A randomized trial of zinc nasal spray for the treatment of upper respiratory illness in adults. Am J Med. 2001;111(2):103-108.

Bilici M, Yildirim F, Kandil S, et al. Double-blind, placebo-controlled study of zinc sulfate in the treatment of attention deficit hyperactivity disorder. Prog Neuropsychopharmacol Biol Psychiatry. 2004;28:181-90.

Cai J, Nelson KC, Wu M, Sternberg P Jr, Jones DP. Oxidative damage and protection of the RPE. Prog Retin Eye Res. 2000;19(2):205-221.

Das UN. Nutritional factors in the pathobiology of human essential hypertension. Nutrition. 2001;17(4):337-346.

Eby GA, Halcomb WW. Ineffectiveness of zinc gluconate nasal spray and zinc orotate lozenges in common-cold treatment: a double-blind, placebo-controlled clinical trial. Altern Ther Health Med. 2006 Jan-Feb;12(1):34-8.

Geerling BJ, Badart-Smook A, Stockbrügger RW, Brummer R-JM. Comprehensive nutritional status in recently diagnosed patients with inflammatory bowel disease compared with population controls. Eur J Clin Nutr. 2000;54:514-521.

Godfrey HR, Godfrey NJ, Godfrey JC, Riley D. A randomized clinical trial on the treatment of oral herpes with topical zinc oxide/glycine. Altern Ther Health Med. 2001;7(3):49-56.

Grahn BH, Paterson PG, Gottschall-Pass KT, Zhang Z. Zinc and the eye. J Am Coll Nutr. 2001;20(2 Suppl):106-118.

Hambridge M. Human zinc deficiency. J Nutr. 2000;130(5S suppl):1344S-1349S.

Intorre F, Polito A, Andriollo-Sanchez M, Azzini E, Raguzzini A, Toti E, et al. Effect of zinc supplementation on vitamin status of middle-aged and older European adults: the ZENITH study. Eur J Clin Nutr. 2007 Jul 11; Epub ahead of print.

Krowchuk DP. Treating acne. A practical guide. Med Clin North Am. 2000;84(4):811-828.

Lawson KA, Wright ME, Subar A, et al. Multivitamin use and risk of prostate cancer in the National Institutes of Health-AARP Diet and Health Study. J Natl Cancer Inst. 2007;99:754-64.

Meyer F, Galan P, Douville P, et al. Antioxidant vitamin and mineral supplementation and prostate cancer prevention in the SU.VI.MAX trial. Int J Cancer. 2005;116:182-6.

Meynadier J. Efficacy and safety study of two zinc gluconate regimens in the treatment of inflammatory acne. Eur J Dermatol. 2000;10:269-273.

Miyata S. Zinc deficiency in the elderly. Nippon Ronen Igakkai Zasshi. 2007;44(6):677-89.

National Academy of Sciences. Dietary Reference Intakes (DRIs): Recommended Intakes for Individuals, Vitamins. Accessed June 1, 2011.

Osendarp SJ, van Raaij JM, Darmstadt GL, Baqui AH, Hautvast JG, Fuchs GJ. Zinc supplementation during pregnancy and effects on growth and morbidity in low birthweight infants: a randomised placebo controlled trial. Lancet. 2001;357(9262):1080-1085.

Papageorgiou PP, Chu AC. Chloroxylenol and zinc oxide containing cream (Nels cream) vs. 5% benzoyl peroxide cream in the treatment of acne vulgaris. A double-blind, randomized, controlled trial. Clin Exp Dermatol. 2000;25:16-20.

Patrick L. Nutrients and HIV: part 2 — vitamins A and E, zinc, B-vitamins, and magnesium. Alt Med Rev. 2000;5(1):39-51.

Polin: Fetal and Neonatal Physiology, 4th ed. Philadelphia, PA: Saunders Elsevier; 2011.

Prasad AS, Fitzgerald JT, Bao B, Beck FW, Chandrasekar PH. Duration of symptoms and plasma cytokine levels in patients with the common cold treated with zinc acetate. A randomized, double-blind, placebo-controlled trial. Ann Intern Med. 2000;133(4):245-252.

Saper R, Rash R. Zinc: An essential micronutrient. Am Fam Phys. 2008;79(9).

Shah D, Sachdev HP. Effect of gestational zinc deficiency on pregnancy outcomes: summary of observation studies and zinc supplementation trials. Br J Nutr. 2001;85 Suppl 2:S101-S108.

Shay NF, Manigan HF. Neurobiology of zinc-influenced eating behavior. J Nutr. 2000;130:1493S-1499S.

Sinclair S. Male infertility: nutritional and environmental considerations. Altern Med Rev. 2000;5(1):28-38.

van Leeuwen R, Boekhoorn S, Vingerling JR, et al. Dietary intake of antioxidants and risk of age-related macular degeneration. JAMA. 2005;294:3101-7.

Zheng L, Zhang L. Efficacy and safety of zinc supplementation for adults, children, and pregnant women with HIV infection: systematic review. Trop Med Int Health. 2011;16(12):1474-82.

Zozaya JL. Nutritional factors in high blood pressure. J Hum Hypertens. 2000;14 Suppl 1:S100-S104.

Review Date: 7/16/2013
Reviewed By: Steven D. Ehrlich, NMD, Solutions Acupuncture, a private practice specializing in complementary and alternative medicine, Phoenix, AZ. Review provided by VeriMed Healthcare Network.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only — they do not constitute endorsements of those other sites. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Zinc Side Effects

Generic Name: zinc sulfate

Medically reviewed by Drugs.com. Last updated on Aug 21, 2019.

  • Overview
  • Side Effects
  • Dosage
  • Professional
  • Interactions
  • More

Note: This document contains side effect information about zinc sulfate. Some of the dosage forms listed on this page may not apply to the brand name Zinc.

For the Consumer

Applies to zinc sulfate: oral capsule, oral tablet

Other dosage forms:

  • intravenous solution

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

  • Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

What are some other side effects of this drug?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if you have any side effects that bother you or do not go away.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch.

For Healthcare Professionals

Applies to zinc sulfate: compounding powder, intravenous solution, oral capsule, oral tablet


Gastrointestinal side effects of zinc sulfate (the active ingredient contained in Zinc) when taken in large doses have included diarrhea, abdominal creams, and vomiting, usually within 3 to 10 hours of dosing. The symptoms go away soon after discontinuation.


Respiratory side effects have included losing sense of smell in patients who use nasal sprays containing zinc.

2. “Product Information. Zinc Sulfate (zinc sulfate).” American Regent Laboratories Inc, Shirley, NY.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

Medical Disclaimer

More about Zinc (zinc sulfate)

  • During Pregnancy
  • Dosage Information
  • Drug Interactions
  • En Español

Consumer resources

  • Zinc

Other brands: Orazinc, Zinc-220

Professional resources

  • Zinc (Advanced Reading)
  • … +1 more

Related treatment guides

  • Vitamin/Mineral Supplementation and Deficiency
  • Dietary Supplementation

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We’ve all been there. I first discovered the health benefits of zinc supplements two years during the holidays.

A few weeks into the craziness of Christmas parties and year end dinners with friends, our body is telling us stop, but the calendar is saying Go!

Partying and poor food choices had me feeling like I was coming down with something, so I reached for the zinc.

I took a product that contains 4 mg of zinc (2 mg if you take one pill), which as we will see in a moment, is actually a perfect dose for most people, but I felt like I needed more, so I “mega-dosed” with a couple 50 mg days. I never did end up getting sick. In fact, I rebounded and ended up feeling great.

50 mg of zinc is a large dose.

Zinc deficiency

Was I deficient?

I believe I did have a mild zinc deficiency (and later confirmed the deficiency with Spectra Cell labs) as a side effect of transitioning to a more plant based diet.

In the western world, acute severe zinc deficiency is rare, but as with magnesium, it’s a real issue that can go unnoticed. However, in the developing world, where zinc deficiency is far more common, it can cause stunted growth, severe immune system dysfunction and even early death.1

It has been estimated that zinc deficiency impacts as many as 2 billion people in third world countries.2

Ok, but I can hear you saying: “John, you lived in Austin, Texas, not the developing world. Why would you have a zinc deficiency?”

I had been eating a lot of food, like oatmeal, that was high in phytic acid, which can block mineral absorption.3 I also regularly supplement with magnesium, and as with many mineral combinations, one can affect the other. Magnesium competes with zinc for absorption, although most of the literature I have seen seems to indicate that taking zinc in excess draws down magnesium, not the other way around.4

On the flip side, I will say that I felt my zinc levels rapidly stabilize with just a few days of 50 mg dosing, and I did take it a bit too far, so much so that I developed some side effects. You do not want to overdo it with zinc. Taking too much zinc will eventually draw down your copper and magnesium levels, both of which can cause health issues.5 I now find that just a few milligrams of zinc 3-4 days per week is ideal for me.

With those personal factors out of the way, what do studies have to say about zinc supplements?

Are there proven benefits?

Benefits of zinc supplements

Zinc boosts the immune system

The research is clear that zinc supplements can have a positive impact on the immune system through a number of different mechanisms. The two primary drivers appear to be IL-2 activation and the corresponding increase in T cells.67 T cells “hunt down” and kill bad cells, like germs/infections and cancer cells.

Zinc increases testosterone

There is evidence that supplementing with zinc can help the body make more testosterone.8

For more tips for optimizing testosterone levels, take a look at the recent interview I did with Dr. Amy Killen, an anti-aging doctor in Utah specializing in sexual optimization.

Histamine intolerance and allergy

I’ve blogged a good bit about histamine intolerance. Histamine is released from immune cells when the body perceives a threat, both real (a virus), or imagined (pollen). When you add the histamine in food and genetic predispositions to the equation, some people begin to develop symptoms.

Zinc has been shown to inhibit the release of histamine from mast cells, which is a blessing for anyone who is trying to bring their histamine levels under control.9

Note: if you’re looking at zinc because of an issue with histamine, remember copper. I am now repeating myself, but copper is a co-factor for diamine oxidase production, the enzyme that clears extracellular histamine. For more, check out our AOC1 gene page.

Zinc and infectious disease

There are multiple studies, in both the elderly and in younger populations, which found zinc plays an important role in combating infectious disease.

Double blind, placebo controlled studies (the gold standard of studies) found zinc supplementation reduced the severity and incidence of diarrhea in infants and young kids in India.10

This study found that zinc supplementation saved the lives of children in developing countries with lower respiratory tract infections.11

Supplementing with zinc has also been shown to decrease the number of infections in the elderly.12

As I mentioned in a men’s health post I did on chronic prostatitis, adequate levels of zinc in the prostate are associated with increased ability to ward off trichomonas vaginalis, a parasite that can infect the prostate gland. This makes sense because zinc levels are 10 times higher in the prostate than in other soft tissue.13

Zinc acts as an antioxidant and decreases oxidative stress

This small (10 subjects), but double blind, placebo controlled study found supplementing with zinc decreased oxidative stress markers in patients who took 45 mg of zinc (again, a large dose in my view).

We’ve touched on oxidative stress in a number of posts, with perhaps the best explanation in our SOD2 A16V post. Put simply, our mitochondria use oxygen as part of the process of generating ATP, which is the energy currency of the body. This is a good thing. But as with any process of burning fuel, there are waste products associated with oxygen metabolism. One of these is called superoxide, which is a harmful free radical that can damage our cells if left unchecked.

In order to neutralize superoxide, our bodies generate a native, or “endogenous,” antioxidant called superoxide dismutase, or SOD. SOD converts the harmful free radical superoxide into the much less harmful hydrogen peroxide, which our bodies further break down from there. But when we lack SOD, and people born with certain variants in this gene are thought to have lower SOD2 levels, our bodies aren’t as good at mopping up free radicals.

Still with me?

Good, because SOD is made up of both copper and zinc.

In our Guide to Nutrigenomics, Aaron also lists zinc as a nutrient that directly enhances expression of the SOD3 gene, as well as for ADA. To quote Aaron:

Zinc, along with copper, is one of two metal co-enzymes required by SOD3 to function 7. There is no evidence demonstrating a beneficial effect on SOD3 activity following zinc supplementation. However, zinc has been shown to demonstrate an antioxidant capacity through unknown means 9, therefore supplementation may benefit those carrying the risk ‘G’ allele of C691G.

Zinc supplement comparison

Brand Formula Quantity
Country Life Zinc 50 mg tablets 100 tablets
TheraZinc Spray 7.4 mg per 8 sprays 4 fl oz
Ionic Zinc 50 mg drops, with 2 mg copper sulfate and magnesium 2 fl oz

Closing thoughts

I think the bottom line here is that, whether you supplement, or eat foods rich in zinc, zinc is a mineral that should be on your radar. It has proven health benefits. However, at large doses over long periods of time many people will experience side effects.

Zinc deficiency is more common than you might think! Severe forms may result in delayed growth, loss of appetite, and other potentially serious consequences. Luckily, it’s easy to meet your daily zinc needs with foods and supplements. Read on to learn all about zinc deficiency, sources, side effects, dosage, and more.

Sources of Zinc

Food Sources

In the United States, pulses and cereals provide about 30%, meat about 50%, and dairy products about 20% of dietary zinc .

Zinc-rich food include :

  • Red meat,
  • Poultry
  • Seafood (oysters, crab, lobster)
  • Eggs
  • Beans
  • Nuts
  • Whole grains
  • Fortified cereals
  • Dairy products

Although whole-grain breads, cereals, and legumes contain phytates that decrease zinc absorption, they are still good sources of zinc .


A number of different forms of zinc are available as supplements, including citrate, sulfate, gluconate, orotate, oxide, picolinate, and acetate .

The percentage of elemental zinc varies by form. In general, organic zinc salts such as citrate and acetate have better absorption, compared with zinc oxide .

Zinc is generally supplemented in:

  • proven zinc deficiency and zinc-losing conditions
  • acrodermatitis enteropathica and Wilson’s disease
  • acute diarrhea in children in developing countries
  • pneumonia and malaria

Zinc Daily Needs and Dosage

General doses may not apply to you personally. If your doctor suggests supplementing with zinc, work with them to find the optimal dosage according to your health condition and other factors.

The Recommended Dietary Allowance (RDA) for zinc (according to the Food and Nutrition Board (FNB) at the Institute of Medicine of the National Academies) :

Age Male Female Pregnancy Lactation
0–6 months 2 mg* 2 mg*
7–12 months 3 mg 3 mg
1–3 years 3 mg 3 mg
4–8 years 5 mg 5 mg
9–13 years 8 mg 8 mg
14–18 years 11 mg 9 mg 12 mg 13 mg
19+ years 11 mg 8 mg 11 mg 12 mg

Optimal zinc dosage may vary based on the individual. As a general rule, 15 mg a day is considered a preventative dosage, while higher doses up to 30 mg may be needed to correct a deficiency.

The Tolerable Upper Intake Level (UL), the highest level of daily nutrient intake that is likely to pose no risk of adverse health effects for almost all individuals, for adults is 40 mg/day.

Zinc Deficiency

Around 10% of persons in the United States have a dietary intake of less than half the RDA of zinc, while over 50% of persons in the third world countries are zinc deficient .

1.4% of deaths worldwide are associated with severe zinc deficiency in childhood .

Zinc deficiency is characterized by delayed growth, loss of appetite, lethargy, impaired immune function and susceptibility to infection .

In more severe cases, zinc deficiency causes hair loss, diarrhea, impaired taste acuity, weight loss, delayed sexual maturation, impotence, testosterone deficiency (hypogonadism) in males, and eye and skin lesions .

Groups at risk for zinc deficiency include :

  • People with digestive disorders
  • Vegetarians
  • Pregnant and lactating women
  • Alcoholics
  • People with sickle cell disease


1) Inadequate Intake

Zinc deficiency may be caused by an inadequate intake of zinc from the diet .

Vegetarians have an increased risk of zinc deficiency because they do not eat meat (high in zinc and may enhance zinc absorption). Their diet is typically rich in legumes and whole grains, but these foods contain phytates that bind zinc and inhibit its absorption .

In developing countries, inadequate zinc intake can occur due to malnutrition.

2) Inadequate Absorption

Several diseases of the digestive system could cause inadequate zinc absorption, including:

Another cause of low iron absorption in the gut is a high intake of food substances that inhibit zinc absorption, such as:

  • Phytates (whole grains, legumes)
  • High intake of fiber

3) Increased loss

Increased zinc loss may occur due to:

Zinc Overload

Zinc overload is uncommon but it can occur due to an overdose or toxic overexposure to zinc .

Consumption of food or beverages contaminated with zinc released from galvanized containers may also lead to zinc toxicity .

Acute adverse effects of high zinc intake (ingesting more than 200 mg/day of zinc) include cramps, nausea, vomiting, diarrhea, loss of appetite, and headaches .

“Zinc shakes”, also known as “zinc chills” or “metal fume fever”, are caused by intense inhalation of fresh industrial fumes containing zinc oxide, and presented as fever, chills, cough, chest pain, and abdominal discomfort .

Prolonged intake of supplemental zinc at doses of 50-300 mg/day can lead to copper and iron deficiency, reduced immune function, and toxicity to the nervous system .

It may also lead to an increase in low-density lipoprotein (LDL) cholesterol and a decline in high-density lipoprotein (HDL) cholesterol, altered heart function, and impaired pancreatic enzymes .

Long-term supplementation with doses over 100 mg/day of zinc increased the relative risk of prostate cancer almost 3 fold due to the immunosuppressive effect of zinc .

Lab Tests for Zinc Status

Low or high levels of zinc don’t necessarily indicate a problem if there are no symptoms or if your doctor tells you not to worry about it. Discuss your lab results with them.

The assessment of zinc status is difficult and challenging because there are no sensitive and specific biomarkers to detect zinc deficiency in humans.

Dietary and medical history and physical examination may all lead to a proper diagnosis.

Laboratory assays for measurement of zinc status:

1) Blood Zinc

Plasma/serum Zinc Concentrations

Normal values for plasma/serum zinc range from 10.7-23.0 µmol/L .

Blood zinc concentration, which represents <0.2% of total body zinc content, is the most frequently measured biomarker of zinc status .

Blood zinc is a useful indicator of the size of the exchangeable zinc pool located in the bone, liver, and blood .

Reductions in dietary zinc beyond the capacity to maintain balance lead to the utilization of zinc from this pool which leads to the rapid onset of both metabolic and clinical signs of zinc deficiency .

Plasma zinc concentration also changes in response to stress, infection, meals, short-term fasting, and the hormonal state .

White Blood Cell Zinc Concentration

White blood cell (neutrophil) zinc reflects levels of tissue zinc accurately, and is thus a very useful parameter of zinc status .

Zinc in the red cells may also be used for assessment of body zinc but the zinc levels do not reflect recent changes with respect to body zinc stores .

Oral Zinc Tolerance Test

The oral zinc tolerance test measures the increase in blood zinc caused by oral ingestion of 25 or 50 mg zinc acetate. The test is quite variable among subjects .

This test has also been used to assess the effects of different foods, meals, vitamin and mineral supplements, diseases and medications on zinc absorption .


Metallothionein is a protein found in most tissues, particularly in the liver, pancreas, and kidney, and binds zinc and copper .

Metallothionein can also be detected in the plasma and red blood cells, and both clearly indicate whether an individual is zinc-deficient because they reflect recent changes in dietary zinc .

Possibly, metallothionein concentrations will also prove to be a useful indicator of changes in dietary zinc .

2) Urinary Zinc

Levels of zinc in the urine usually range from 0.3-0.6 mg/day .

The measurement of zinc in a 24-hr urine sample is helpful for diagnosing zinc deficiency in healthy individuals. Urinary excretion of zinc is decreased as a result of zinc deficiency .

Many diseases such as cirrhosis of the liver, sickle cell disease, chronic kidney disease, burns, and starvation, are characterized by excessive urinary zinc excretion, thus these conditions should be eliminated .

3) Hair Zinc

Hair zinc levels of less than 1.07 µmol/g probably reflect a chronic suboptimal zinc status in children. The validity of the hair zinc level as an indicator of chronic suboptimal zinc status in adults remains uncertain .

Hair zinc analysis cannot be used in cases of severe zinc deficiency or malnutrition because the rate of hair growth is decreased in malnourished patients. In such cases, hair zinc concentrations may be normal or even high .

Hair zinc concentrations vary with hair color, season, sex, age, anatomical site of sampling and rate of hair growth. These factors must be considered when interpreting hair zinc concentrations .

4) Taste Acuity

Diminished taste acuity (hypogeusia) is a symptom of zinc deficiency, and it has been used as a functional test of zinc status (75).

In a taste acuity test, solutions of varying concentrations of the four different taste qualities (salt, sweet, bitter, and sour) are used. The test is based on the detection and recognition thresholds for each taste quality .

Zinc taste tests should be performed midmorning, at least 2 h after a meal, and by the same person on each occasion .

This list does not cover all possible side effects. Contact your doctor or pharmacist if you notice any other side effects. In the US, you may report side effects to the FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada, you may report side effects to Health Canada at 1-866-234-2345.

Generally, zinc supplements are safe and well tolerated in adequate amounts.

Short term effects of zinc toxicity include nausea, vomiting, diarrhea, headaches, stomach cramps, loss of appetite, and irritability .

Long term effects of high zinc intake (150 – 450 mg/day) have been linked to copper deficiency, impaired iron function, depressed immunity, and low levels of high-density lipoproteins (HDL) .

Zinc supplements are likely safe for children and pregnant women, too, but they should consult with their doctors before supplementing.

Interactions With Medications

Nutrient-drug interactions can be dangerous and, in rare cases, even life-threatening. Always consult your doctor before supplementing and let him know about all drugs and supplements you are using or considering.

1) Penicillamine

Zinc can reduce the absorption and effectiveness of penicillamine, a drug used to treat rheumatoid arthritis and Wilson’s disease. Zinc and penicillamine should be taken at least 2 hours apart .

2) Antibiotics

Both quinolones (Cipro®, Levaquin®) and tetracyclines (Achromycin®, Minocin®) decrease the absorption of zinc in the gut, and vice versa .

Taking the antibiotic at least 2 hours before or 4 – 6 hours after taking a zinc supplement minimizes this interaction.

3) Diuretics (Water Pills)

Prolonged use of thiazide diuretics (Hygroton®, Esidrix®, and HydroDIURIL®) could deplete zinc levels by increasing zinc removal in the urine by as much as 60% .

Amiloride (Midamor®) can increase the amount of zinc in the body .

4) Blood Pressure Medication

ACE inhibitors (Capoten®, Vasotec®, Monopril®) and angiotensin receptor blockers (Edarbi®, Atacand®) used to treat high blood pressure, may decrease the levels of zinc in the blood .

5) Cisplatin

Cisplatin, used to treat some types of cancers, increases urinary zinc excretion thus decreasing blood levels of zinc in patients treated with cisplatin .

Interactions With Nutrients & Food

1) Iron

High doses of zinc can interfere with the absorption of iron .

Iron supplements, taken together with zinc supplements on an empty stomach, may inhibit the absorption of zinc.

When taken with food, supplemental iron does not inhibit zinc absorption .

2) Copper

Zinc supplementation can interfere with the absorption of copper, and cause a copper deficiency which has been reported in humans using up to 600 mg elemental zinc daily or excessive usage of zinc-based dental adhesives .

3) Alcohol

Alcohol decreases the absorption of zinc and increases urinary zinc excretion .

4) Calcium

Excessive dietary calcium decreases zinc absorption .

5) Protein

Protein enhances zinc absorption .

6) Phytates and Fiber

Phytates and fiber (present in vegetables, whole grains, cereals, and legumes) bind to zinc and inhibit its absorption .

7) Chlorogenic Acid

Chlorogenic acid (commonly found in coffee) can decrease zinc absorption .

8) Vitamin A

Zinc has been shown to increase Vitamin A levels in the blood .

9) Vitamin B6 and Magnesium

Zinc is commonly supplemented with Vitamin B6 and magnesium in the formulation known as ZMA, used primarily by athletes as it is claimed to be a testosterone booster .


Possible Interactions with: Zinc

Also listed as: Zinc

Table of Contents > Supplement Interactions > Possible Interactions with: Zinc

If you are being treated with any of the following medications, you should not use zinc without first talking to your health care provider.

Amiloride (Midamor) — Amiloride is a potassium-sparing diuretic (water pill) that may increase the levels of zinc in your blood. Do not take zinc supplements if you take amiloride.

Blood pressure medications, ACE Inhibitors — A class of medications called ACE inhibitors, used to treat high blood pressure, may decrease the levels of zinc in your blood. ACE inhibitors include:

Antibiotics — Zinc may decrease your body’s absorption of two kinds of antibiotics, quinolones and tetracyclines. These include:

  • Ciprofloxacin (Cipro)
  • Levofloxacin (Levaquin)
  • Ofloxacin (Floxin)
  • Moxifloxacin (Avelox)
  • Norfloxacin (Noroxin)
  • Gatifloxacin (Tequin)
  • Tetracycline
  • Minocycline (Minocin)
  • Demeclocycline (Declomycin)

However, doxycycline (Vibramycin) does not seem to interact with zinc.

Cisplatin (Platinol-AQ) — This drug, used for chemotherapy to treat some types of cancers, may cause more zinc to be excreted in your urine. If you are undergoing chemotherapy, do not take zinc or any other supplement without talking to your oncologist.

Deferoxamine (Desferal) — This medication, used to remove excess iron from the blood, also increases the amount of zinc that is lost in urine.

Immunosuppressant medications — Since zinc may make the immune system stronger, it should not be taken with corticosteroids (such a prednisone), cyclosporine, or other medications intended to suppress the immune system.

Nonsteroidal anti-inflammatory drugs (NSAIDs) — Zinc interacts with NSAIDs and could reduce the absorption and effectiveness of these medications. Examples of NSAIDs, which help to reduce pain and inflammation, include ibuprofen (Advil, Motrin), naprosyn (Aleve), piroxicam (Feldene), and indomethacin (Indocin).

Penicillamine — This medication, used to treat Wilson’s disease (where excess copper builds up in the brain, liver, kidney, and eyes) and rheumatoid arthritis, decreases the levels of zinc in your blood.

Thiazide diuretics (water pills) — This class of medications lowers the amount of zinc in your blood by increasing the amount of zinc that is passed in your urine. If you take thiazide diuretics, your doctor will monitor levels of zinc and other important minerals in your blood:

  • Chlorothiazide (Diuril)
  • Hydrochlorothiazide
  • Chlorthalidone (Hygroton)
  • Indapamide (Lozol)
  • Metolozone (Zaroxolyn)
  • Polythiazide (Renese)
  • Quinethazone (Hydromox)
  • Trichlormethiazide (Metahydrin, Naqua, Diurese)

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Zinc is a mineral and co-factor for numerous emzymes that is involved in many biochemical pathways, including DNA and protein synthesis. Zinc is considered to be an “essential” nutrient that can be obtained through diet. Other than iron, zinc is the most prevalent mineral in the human body as it can be found in every cell. Zinc is essential for growth and plays a role in visual function, wound healing, immune, reproduction, taste sensation, hearing, smell, blood clotting, and insulin and thyroid function. As an antioxidant, zinc plays a role in cell protection, by helping shield cells from harmful free radicals that are thought to contribute to aging and other health problems. It also has anti-viral properties against some viruses (eg. Rhinovirus and herpes simplex virus). Zinc is especially necessary during pregnancy and childhood as it plays a significant role in growth.

Although it is rare for people in industrialized countries to have severe zinc deficiency, populations at risk for deficiency include the elderly, alcoholics, anorexic people, people on strict diets, and those with Crohn’s disease or celiac disease.

Zinc deficiency can be recognized by the following symptoms:

  • Loss of appetite
  • Insufficient growth
  • Weight loss
  • Impaired taste sensation or smell properly
  • Unusually slow wound healing
  • Skin issues
  • Hair loss
  • Absent menstrual period
  • Blindness at night
  • White spots appearing on the fingernails
  • Persistant depression
  • Anorexia
  • PICA
  • Depression
  • Dermatitis
  • Diarrhea
  • Low sperm count
  • Night Blindness
  • Anemia

Zinc limits the amount of copper your body is able to absorb and therefore a large amount of zinc can possibly result in copper deficiency.

Also known as: Acétate de Zinc, Acexamate de Zinc, Aspartate de Zinc, Chlorure de Zinc, Citrate de Zinc, Gluconate de Zinc, Méthionine de Zinc, Monométhionine de Zinc, Numéro Atomique 30, Orotate de Zinc, Oxyde de Zinc, Picolinate de Zinc, Pyrithione de Zinc, Sulfate de Zinc, Zinc Acetate, Zinc Acexamate, Zinc Ascorbate, Zinc Aspartate, Zinc Chloride, Zinc Citrate, Zinc Difumarate Hydrate, Zinc Gluconate, Zinc Methionate, Zinc Methionine, Zinc Monomethionine, Zinc Murakab, Zinc Orotate, Zinc Oxide, Zinc Picolinate, Zinc Pyrithione, Zinc Sulfate, Zinc Sulphate, Zincum Aceticum, Zincum Gluconicum, Zincum Metallicum, Zincum Valerianicum

Diseases and Conditions

Zinc is effective for treating the following conditions:

  • Zinc deficiency

Zinc is likely effective for treating the following conditions:

  • Diarrhea
  • Wilson’s disease
  • Acne
  • Acrodermatitis enteropathica
  • Age-related macular degeneration
  • Anorexia nervosa
  • Attention deficit-hyperactivity disorder
  • Burns
  • Colorectal adenoma
  • Common cold
  • Depression
  • Diabetic foot ulcers
  • Diaper rash
  • Gingivitis
  • Halitosis
  • Herpes simplex virus
  • Hypogeusia
  • Leishmania lesions
  • Leprosy
  • Muscle cramps
  • Osteoporosis
  • Peptic ulcers
  • Pneumonia
  • Pregnacy-related complications
  • Pressure ulcers
  • Shigellosis
  • Sickle cell disease
  • Venous leg ulcers
  • Vitamin A deficiency
  • Warts

Zinc is likely ineffective for treating the following conditions:

  • AIDS diarrhea-wasting syndrome
  • Alopecia areta
  • Eczema
  • Cataracts
  • Cystic fibrosis
  • Infant development
  • Inflammatory bowel disease
  • Influenza
  • Otisis media
  • Pregnancy-related iron deficiency
  • Prostate cancer
  • Psoriasis
  • Rheumatoid arthritis
  • Rosacea
  • Sexual dysfunction
  • Tinnitus
  • Upper respiratory tract infections.

Zinc is likely ineffective for treating the following condition:

  • Malaria


Zinc is likely safe when used orally and appropriately within the tolerable upper intake level (UL) of 40 mg/day. It may be safe to take zinc in higher doses under the supervision of a physician. Zinc is possibly unsafe when used intranasally since it might cause permanent anosmia or loss of sense of smell. It is likely unsafe to ingest large doses of zinc; 10-30 grams of zinc sulfate can be lethal for adults. Children, pregnant, and breastfeeding women may safely take zinc under the supervision of a physician.

Zinc is generally well-tolerated when taken within the tolerable upper intake level of 40mg/day for adults. However, possible side effects may include gastrointestinal disturbances nausea and vomiting.

When taken in amounts above your recommended amount, zinc may cause serious adverse effects, including:

  • Copper deficiency and associated symptoms
  • Watery diarrhea
  • Irritation and corrosion of the gastrointestinal (GI) tract
  • Acute renal tubular necrosis
  • Interstitial nephritis

Topically, zinc may cause the following side effects:

  • Burning
  • Stinging
  • Itching
  • Tingling when applied to inflamed tissue

Topical exposure to zinc oxide can cause dark discoloration of the skin, especially following prolonged topical application to intact skin, application to eroded or ulcerated skin, or penetrating traumatic exposure, and also parenteral administration.

Medication Interactions

Zinc may interfere with the following medications:

  • Amiloride
  • Antidiabetes drugs, such as:
    • Glimepiride (Amaryl)
    • Glyburide (DiaBeta, Glynase PresTab, Micronase)
    • Insulin
    • Metformin (Glucophage)
    • Pioglitazone (Actos)
    • Rosiglitazone (Avandia)
    • Atazanavir
    • Cephalexin
    • Cisplatin
  • Integrase inhibitors such as:
    • Dolutegravir (Tivicay)
    • Elvitegravir (Vitekta)
    • Raltegravir (Isentress)
  • Penicillamine
  • Quinolones such as:
    • Ciprofloxacin (Cipro)
    • Levofloxacin (Levaquin)
    • Ofloxacin (Floxin)
    • Moxifloxacin (Avelox)
    • Gatifloxacin (Tequin)
    • Ritonavir
    • Tetracycline antibiotics

Supplement and Food Interactions

Zinc may potentially interfere with the following herbs, supplements, and foods:

  • Beta-carotene
  • Bromelain
  • Calcium
  • Chromium
  • Copper
  • EDTA
  • Folic acid
  • Herbs and supplements with hypoglycemic effects, including:
    • Alpha-lipoic acid
    • Bitter melon
    • Chromium
    • Devil’s claw
    • Fenugreek
    • Garlic
    • Guar gum
    • Horse chestnut
    • Panax ginseng
    • Psyllium
    • Siberian ginseng
    • Phytic acid
    • Iron
    • Magnesium
    • Manganese
    • Riboflavin
    • Vitamin A
    • Vitamin D
  • Coffee
  • Dairy
  • Calcium-fortified foods
  • Fiber
  • Phytate
  • Protein
  • Vegetarian diet


The correct dosage of any supplement requires a comprehensive analysis of many factors including your age, sex, health conditions, DNA, and lifestyle.

For adults, the following Recommended Dietary Allowance (RDA) of zinc have been established but may vary based on your individual profile:

  • Girls and women 14-18 years: 9 mg/day
  • Boys and men age 14 and older: 11 mg/day
  • Women 19 and older: 8 mg/day
  • Pregnant women 14 to 18: 13 mg/day
  • Pregnant women 19 and older: 11 mg/day
  • Lactating women 14 to 18: 14 mg/day
  • Lactating women 19 and older: 12 mg/day


Zinc can be found in the following foods:

  • Red meat
  • Poultry
  • Fish
  • Spinach
  • Kidney Beans
  • Flax seeds
  • Pumpkin Seeds
  • Watermelon seeds
  • Garlic
  • Lima Beans
  • Peanuts
  • Seafood
  • Whole Grains
  • Wheat germ
  • Wheat Bran
  • Egg Yolk
  • Nuts
  • Legumes

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