Zinc Deficiency: 9 Signs, Causes and the Best Foods to Fix It

Zinc deficiency most often shows up as frequent colds, slow-healing cuts, fading taste or smell, thinning hair or skin rashes, because zinc is the mineral your body relies on to fight infections and repair tissue.12 My approach is food first, with grass-fed beef, lamb and pumpkin seeds, then fixing whatever is blocking absorption, and adding 15 to 30 mg of zinc a day with food when a test shows you're low.18

Low zinc can start with what's on your plate, and it can also start with what blocks or drains it. That's the root cause I look for: grains and beans that were never soaked, sprouted or fermented, low stomach acid or acid-blocking medicine, an inflamed gut, heavy drinking and chronic stress.16 Pregnancy, breastfeeding and older age raise the odds as well, because your needs climb or your intake falls short.64

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Maybe you catch every cold that goes around, a small cut seems to take forever to close, or food has started to taste a little flat. Each of those can trace back to low zinc. Your body was designed to heal, and once it has enough zinc again, it can get back to the defense and repair work this mineral makes possible.

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What is zinc deficiency?

Zinc plays a part in your immune function, in making protein and DNA, in wound healing, in cell signaling and division, in growth, and in your sense of taste.6 So when it runs low, the effects show up in several places at once, which is why the signs below can look unrelated at first.

Severe deficiency is uncommon in the U.S. and much more common in low- and middle-income countries.6 Worldwide, an estimated 17.3% of people are at risk of not getting enough zinc, and that risk rises where diets carry more phytate, a compound in grains and beans that binds zinc, and falls where more of the zinc comes from animal foods.10

How zinc works in your body

Zinc is part of how your body builds, repairs and defends itself. It helps more than 300 enzymes do their jobs, and it's needed by more than 1,000 transcription factors, the switches that turn genes on and off in your cells.4 Your immune cells even use zinc as a messenger to pass signals along.4 That reach is why one mineral can touch your immune system, skin, gut, taste and hormones all at once.

The discovery of how much zinc matters began in Shiraz, Iran, where the physician Ananda Prasad was shown a 21-year-old man who looked like a 10-year-old boy. He was severely anemic, his skin was rough and dry, and he ate only bread made from whole wheat flour, with no animal protein at all.4 Prasad found the same pattern in the surrounding villages, and his later studies in Egypt showed that zinc gave young people with this condition 12.7 to 15.2 cm (about 5 to 6 inches) of growth in a single year.4 He went on to name phytate-heavy cereal diets as the major driver of zinc deficiency in the developing world, and by 1974 zinc had its own recommended daily allowance in the U.S.4

Even a mild shortfall changes how you feel and function. When researchers lowered zinc intake in healthy volunteers, the men's testosterone fell, their natural killer cells and helper T cells became less active, thymulin (a hormone from the thymus gland that helps T cells mature) dropped, their sense of taste dulled, their eyes adapted to the dark more slowly, and they lost lean body mass.4 This is how a shortfall builds, and where your body shows it first:

The plan follows that same order: zinc-rich food fills the supply, preparing your grains and beans and caring for your gut help you absorb it, testing with the blood test's limits in mind tells you where you stand, and a targeted supplement refills what's low.

Zinc deficiency symptoms: 9 signs to watch for

My bloodwork guide lists frequent infections, slow wound healing, loss of taste and smell, hair loss, acne and low testosterone as the signs of a zinc shortfall, and the research adds diarrhea, a fading appetite and low mood.126 Each of these can have other causes too, so if two or more sound like you, test before you reach for a supplement.

1. Frequent colds and infections

If you catch colds easily, or each one drags on for weeks, zinc belongs near the top of your list. Your immune cells need zinc to develop and to defend you against viruses, and low zinc prolongs illness.8 A year-long trial in older adults, a group prone to running low, shows how much difference it can make. At a Detroit senior center, 50 healthy adults aged 55 to 87 took 45 mg of zinc a day, as zinc gluconate, or a placebo for 12 months, and neither the people nor the researchers knew who got what. Among the 49 who finished, the zinc group averaged 0.29 infections per person over the year, against 1.4 on placebo, and their markers of inflammation and oxidative stress fell too.34 The trial used 45 mg a day as its research dose, and the daily-amount section below gives my own range for low zinc.

The same link shows up in nursing homes. In an observational study of 420 nursing home residents in Boston, those whose serum zinc was normal at the end of a year got pneumonia less often and needed almost 50% fewer new antibiotic prescriptions than residents whose zinc was low.15 For colds that are already underway, zinc lozenges are a separate, short-term tool, covered with the supplements below, and our guides to natural cold remedies and how to boost your immune system cover the rest. When colds start making the rounds each fall and winter, a zinc-rich dinner is one of the simplest things you can do for your immune defenses.

2. Changes in taste and smell

When food starts tasting flat or strange, or your sense of smell dulls, low zinc is one of the first things to rule out.1 Zinc is part of how your sense of taste works, and in the volunteer studies above, even a mild shortfall dulled it.64 In a placebo-controlled trial of 50 people with a distorted sense of taste that had no clear cause, 140 mg of zinc gluconate a day improved their taste function and their mood scores, and they rated the problem as less severe.16 A Cochrane review of 9 placebo-controlled zinc trials in 544 people found that zinc sharpened taste on objective tests: in the 2 trials that counted improvement, with 292 people who had low zinc or taste loss with no clear cause, those taking zinc were 42% more likely to improve, although their own ratings didn't show a clear difference and the reviewers rated the evidence very low in certainty.17 If taste is your main sign, put serum zinc and copper on your next blood draw and lean on the food list below, where 3 ounces of beef chuck covers more than half of an adult's daily need.

3. Slow wound healing

Your skin's outer layer is rich in zinc, and even a mild deficiency can leave skin rough and slow to heal.12 Zinc supports each stage of repair, so a cut, scrape or sore that lingers for weeks is worth a second look.12 For leg ulcers, a Cochrane review of 6 small trials in 183 people found no clear difference in healing with oral zinc sulfate.18 What matters while a wound heals is that you aren't running low, so keep zinc-rich protein foods at your meals and get a test if healing stalls. Our guide to wound care covers the rest of the healing basics.

4. Hair loss

Thinning hair or heavier shedding is on my list of zinc signs, and blood work in people with hair loss points the same way.1 In a Korean hospital study, 312 people with four types of hair loss had lower serum zinc on average than 30 healthy people, 84.33 against 97.94 mcg/dL, while their copper levels didn't differ.19 Low zinc was especially common in alopecia areata, which causes patchy hair loss, and in telogen effluvium, a pattern of heavy shedding.19 In one documented case, hair loss blamed on an underactive thyroid improved only after zinc was added to the thyroid medication.20 If your hair is thinning, test zinc and copper together, and these hair loss remedies can work alongside the food steps on this page.

5. Skin rashes and acne

Rough, dry skin, rashes and stubborn acne can all trace back to low zinc.21 In a pooled review of acne studies, people with acne had lower serum zinc than people without it, and zinc treatment reduced the number of inflamed acne bumps, with no more side effects than the comparison treatments.21 In my practice, acne has cleared for some patients once we changed their diet, for others once I gave them a zinc supplement, and for others once their stress came down, because what works really depends on the person.22 A rare inherited condition that blocks zinc absorption from infancy also starts with a rash, and the FAQ explains it. Along with the zinc foods below, these home remedies for acne work on your skin from the outside in.

6. Diarrhea

Diarrhea is both a sign of low zinc and a cause of it, because zinc helps keep your gut lining intact, and long-running diarrhea is one of the ways your body loses zinc.62 In infants and young children, diarrhea is a common sign of low zinc.6 A Cochrane review of 33 trials in 10,841 children aged 1 month to 5 years, mostly in Asian countries where low zinc is common, found that in children older than 6 months, zinc shortened diarrhea by about half a day and made it 27% less likely to last a full week. In children who were also malnourished, it shortened diarrhea by about a day, while in babies under 6 months it made no clear difference.23 The World Health Organization's 2024 guideline recommends oral zinc as an add-on treatment for acute watery or persistent diarrhea in children up to age 10, and it now suggests a 5 mg daily dose for 10 to 14 days, lower than its earlier course, because the smaller dose works as well with less vomiting.24 For adults, our guide on how to stop diarrhea covers the food side, and if your diarrhea comes from a gut condition, zinc belongs on your test list.

7. Poor appetite and weight loss

A fading appetite is a classic sign of low zinc, and it can feed on itself, since eating less brings in even less zinc.26 In a placebo-controlled trial of 35 women being treated in the hospital for anorexia nervosa, 100 mg of zinc gluconate a day helped them regain weight, measured as body mass index, twice as fast as placebo did.25 If your appetite has faded along with other signs on this list, start with small, zinc-rich meals, and our guide to loss of appetite has more ideas for getting your hunger back.

8. Low mood and foggy thinking

In older adults, low zinc can change how you think and feel.6 Across 17 observational studies, people with depression had blood zinc about 1.85 µmol/L lower than people without it, and the more severe the depression, the lower the zinc.26 A 2022 pooled analysis found that people who ate the most zinc had about a third lower risk of depression (relative risk 0.66) than those who ate the least, and in randomized trials, zinc given on its own lowered depression scores by 4.15 points.27 Low mood has many roots, and our guide to natural remedies for depression covers the others, so add zinc to your test list if a cloudy head or low mood travels with the other signs here.

9. Low testosterone and low libido

Low zinc is one of the root causes I look for in men with low testosterone, along with insulin resistance, low vitamin D, poor sleep and high cortisol. I've called pumpkin seeds one of the best foods for testosterone, because they're high in zinc, which is critical for testosterone production.28 A Wayne State University study shows why. When 4 healthy young men ate a low-zinc diet for 20 weeks, their testosterone fell from 39.9 to 10.6 nmol/L, and when 9 older men with marginal zinc deficiency took about 30 mg of zinc a day as zinc gluconate for 3 to 6 months, their testosterone nearly doubled, from 8.3 to 16.0 nmol/L, though that older group had no comparison group.13

With a lot of the men I take care of, I put together a food plan that includes many testosterone-supporting foods, grass-fed beef and pumpkin seeds among them, and I'll sometimes have them add a tablespoon of sprouted pumpkin seed butter to a morning smoothie.28 Our guide on how to increase testosterone covers the sleep, training and other food steps that work alongside zinc.

Signs that build over years

When a shortfall runs for years, especially in childhood, it can slow growth and delay sexual development, and at any age it can dull your ability to see in dim light.24 The young man in Shiraz is the extreme version of that pattern, and the zinc-rich foods and absorption steps below are how you keep from ever getting close to it.

What causes zinc deficiency?

What drains zinc, and where to start

Plant-heavy diets and phytate

Phytate explains much of why the same amount of zinc can feed you well from one meal and poorly from another. People who eat vegetarian diets typically eat a lot of beans and whole grains, which carry phytate, and they skip meat, which is high in absorbable zinc, so they usually take in less zinc and have lower serum levels.6 Across 26 studies, vegetarians took in 0.88 mg less zinc a day and had lower serum zinc than non-vegetarians, and the gap was bigger in women and in vegans.29 The requirement for zinc may be as much as 50% greater for vegetarians.2

On long-term vegan and raw diets, I see deficiencies in zinc and in omega-3 fats such as EPA, and from a Chinese medicine standpoint, that way of eating weakens digestion, which in turn weakens the immune system.31 If you eat vegan or raw, I want you to get bloodwork done to see where you stand.31 You can still keep your zinc up on a plant-heavy plate by soaking, sprouting and fermenting your grains and beans and leaning on pumpkin seeds and hemp seeds, as the food section below shows, and our guide to the vegan diet covers the other nutrients to watch.

A gut that can't absorb it

Your intestines are where zinc gets absorbed, so a struggling gut can leave you low even when you eat well.116 About 15% to 40% of people with inflammatory bowel disease have zinc deficiency, whether their disease is active or in remission, and about half of people newly diagnosed with celiac disease are at high risk.6 Low zinc also makes gut disease harder: in a registry of 773 people with Crohn's disease, those with low serum zinc had about twice the odds of needing surgery (odds ratio 2.05), and in 223 people with ulcerative colitis, the odds of a hospital stay were 2.14 times higher.32

Zinc also helps the gut lining repair itself. In a small study of 12 people with Crohn's disease in remission whose gut lining had become more permeable, 8 weeks of zinc sulfate (110 mg three times a day) brought their gut permeability down on a sugar-absorption test (the score fell from 0.041 to 0.026), and the study had no comparison group. Over the next year, 10 of the 12 kept normal permeability and stayed in remission.14 That's why zinc is part of how I approach leaky gut, and the supplement section below explains the form I use for the gut.

Low stomach acid and acid blockers

Stomach acid helps your gut absorb minerals, and acid blockers and antacids are on my list of root causes for low zinc.111 In a before-and-after study of 14 healthy volunteers, a week of the acid blocker omeprazole cut how much zinc they absorbed from a test dose by about 40%.11 If you live with reflux, the free Acid Reflux & GERD protocol covers the food steps that ease it, and the zinc-rich foods below help keep your levels up in the meantime.

How do you test for zinc deficiency?

A blood test is the place to start, and knowing its limits helps you read it well. Serum zinc shifts with your age and sex, the time of day it's drawn and whether you've just eaten, and it can drop during an infection, with changes in steroid hormones, or when you're losing weight or ill.69 So a mild shortfall can sit inside the normal range, and a low number isn't always a true deficiency. In an audit of 70 patients prescribed zinc in Scotland, 48% had low plasma zinc that was probably caused by low albumin or inflammation rather than a real lack of zinc.33 A morning draw, with CRP and albumin alongside, gives you a much clearer read, and a functional medicine practitioner can put the results together with your symptoms.

My bloodwork guide includes RBC zinc, the zinc inside your red blood cells, because I prefer to look at what's inside your cells, and it includes your copper-to-zinc ratio, because these two minerals work as a pair.1 Hair analysis isn't a reliable test for zinc, since the expert panel that reviewed zinc tests found too little data to recommend hair zinc.9

Zinc tests, and how to read them

What are the best foods for zinc deficiency?

Food is the first medicine for low zinc. Beef supplies about 20% of the zinc Americans get from food, and meals built on animal foods deliver zinc you absorb more completely than mixed or plant-heavy meals do.6 Grass-fed beef, lamb and pumpkin seeds sit at the top of my zinc list.1 Grass-fed beef is high in zinc, and I recommend going leaner, with cuts such as filet mignon or 90/10 ground beef.28

Zinc in everyday foods. Per 100 g values are from USDA FoodData Central; per-serving values are calculated from them using the serving weights shown.5

On a plate, 3 ounces of braised beef chuck covers 60% of the 11 mg daily value, and an ounce of pumpkin seeds adds another 20%.56 Keep red meat fresh, unprocessed and grass-fed. The International Agency for Research on Cancer classifies processed meat of every kind, processed beef included, as Group 1, carcinogenic to humans, and red meat itself as Group 2A, probably carcinogenic.34 As I've said on my show, the studies that link red meat to poor health mostly reflect grain-fed and processed meat, not the fresh, grass-fed red meat I recommend.35

You'll find oysters at the top of most zinc lists, but they're shellfish, and I follow the fins-and-scales standard of the biblical diet: "These shall ye eat of all that are in the waters: whatsoever hath fins and scales in the waters, in the seas, and in the rivers, them shall ye eat" (Leviticus 11:9, KJV). Grass-fed beef, lamb, bison and pumpkin seeds give you plenty of zinc without them, and our full list of foods high in zinc has more choices.

How to absorb more zinc from seeds, grains and beans

Phytate, one of the antinutrients in grains, beans, nuts and seeds, binds zinc in your gut, so the share of zinc you absorb from a meal can range from 5% to more than 50% depending on how much phytate the diet carries.6 Keep these foods on your plate, since they bring fiber, minerals and plant compounds you want, and prepare them in ways that free up more of their zinc. I teach that sprouting and fermenting lower phytic acid and make more of the iron, zinc, calcium and magnesium in these foods available to your body.8 That's why, historically, almost all grains were either sprouted or fermented: it broke down the phytic acid and let people fully absorb those nutrients.36

Leavening shows how well this works. When researchers leavened bran bread, its phytate fell to about 40% of the starting level after 2 hours and to 15% after 2 days, and in 42 student volunteers, the share of zinc they absorbed from the bread rose as fermentation time lengthened.7 Soaking beans, grains and seeds in water for several hours before cooking helps too, canned and pre-cooked beans are another option, and the organic acids in fermented foods may raise zinc absorption.6 In practice, that means:

• Soak dried beans, lentils and whole grains for several hours, or overnight, before you cook them.6
• Choose sourdough bread or sprouted grain bread over quick-rise bread.78
• Buy sprouted seeds and nut butters, or soak raw nuts and seeds yourself.8
• Add a fermented food, such as sauerkraut or other fermented vegetables, to meals built on grains and beans.6

How much zinc do you need a day?

The Recommended Dietary Allowance, the amount that covers nearly all healthy people, depends on your age, sex and life stage. The upper limit is the most you can take in each day, from food and supplements together, without expecting harm.6

Zinc a day by age, in milligrams. For babies up to 6 months, the figure is an Adequate Intake.6

Average intakes from food run about 13 mg a day for men and 9.2 mg for women, so most adults come close.6 Teenage girls and older adults are more likely to fall short: 20.9% of girls aged 14 to 18 take in less than the average requirement, and the RDA doesn't drop after 50 even though many older adults eat less.64

If a test shows you're low, I recommend 15 to 30 mg of zinc a day as picolinate, citrate or glycinate, taken with food, on top of zinc-rich meals.8 Count the zinc in your multivitamin toward that range, since the elemental zinc on each Supplement Facts panel adds up. Plan to retest after about 3 months, so you can see where you stand and adjust from there.

Zinc supplements and copper: how to keep them in balance

Copper is the piece that's easy to miss when you start a zinc supplement, because the two minerals work as a pair.1

That same Scottish audit of 70 patients shows how easily the copper side gets overlooked: 62% were on doses high enough to cause copper deficiency, and copper was measured in only 2 of them.33 So for long-term use, I pair zinc with 1 to 2 mg of copper, and I recommend taking it apart from calcium and iron.1 Iron matters here because 25 mg of iron or more taken at the same time as zinc can lower how much zinc you absorb.6

I'd rather you get zinc and copper together from food when you can, such as a spoonful of pumpkin seed butter, because food brings along the co-factors that help your body absorb and use them.37 An ounce of roasted pumpkin seeds brings 0.36 mg of copper along with its 2.2 mg of zinc, and an ounce of raw cashews carries 0.62 mg of copper.5 Beef liver carries both in large amounts, 4.4 mg of zinc and about 12.4 mg of copper in 3 ounces,5 and I recommend about 3 ounces once a week, unless your bloodwork shows your vitamin A running high. For more ideas, see these foods high in copper, and our guide to copper deficiency explains the signs on the other side of the balance.

The form on the label makes a difference, too. In one comparison in young adults, zinc citrate and zinc gluconate were each about 61% absorbed and zinc oxide 50%.6

Zinc carnosine for the gut lining

For the gut itself, I use a different form: in my leaky gut protocol, it's zinc carnosine, zinc bound to the compound carnosine, at 75 mg twice a day with food, and I've used it with many patients to help heal their gut.3839 In a trial in which 10 healthy volunteers each tried both, 5 days of the painkiller indomethacin tripled gut permeability on placebo, but permeability didn't rise significantly when they took zinc carnosine (37.5 mg twice a day) alongside it.40 The free Healing Leaky Gut protocol lays out where zinc carnosine fits with the rest of the gut repair steps.

Zinc lozenges in cold season

When a cold has already started, zinc lozenges are a short course for a few days, separate from correcting a deficiency. In a pooled analysis of 3 placebo-controlled trials in 199 adults with colds, zinc acetate lozenges supplying 80 to 92 mg of zinc a day, started early, left 70% of people recovered by day 5, against 27% on placebo.41

A 2024 Cochrane review of 34 trials found colds were about 2.37 days shorter when people took zinc as a treatment (8 trials, 972 people, low certainty), while taking zinc to prevent colds made little or no difference.42 So keep lozenges for when a cold starts: begin within 24 hours of your first symptoms, use them for a few days, then return to your everyday food and supplement amounts.41

Zinc-rich recipe ideas

Zinc-rich cooking doesn't need to be complicated, and here are seven easy ways to put more zinc on your plate:

• Spicy pumpkin seeds: roast the seeds from your carving pumpkin with spices for a crunchy snack.
• Garlic lamb roast: a Sunday roast built on lamb, one of the top zinc foods in the table above.
• Beef stew: slow-cooked beef and vegetables, a cold-weather way to eat the top food in the table.
• Slow-cooker bison chili: grass-fed bison with black and kidney beans in one pot; canned beans work well here.
• Hummus: chickpeas and tahini blended together, two zinc foods in one dip.
• Red lentil soup: a warming bowl of lentils for chilly evenings.
• Pumpkin seed butter smoothie: the morning smoothie from the testosterone section, with a tablespoon of sprouted pumpkin seed butter, a scoop of protein, and water, coconut milk or berries.28

Too much zinc, and who should be careful

Count every source. The upper limits in the daily-needs table above count food and supplements together, including your multivitamin and any lozenges.6 In the Scottish audit described above, 9% of the patients taking zinc developed unexplained anemia and 7% developed nerve symptoms typical of low copper.33 Heavy, long-term use of denture creams that contain zinc has caused copper deficiency and nerve problems, so choose a zinc-free cream if you use a lot of it.6

Medications. Zinc binds quinolone and tetracycline antibiotics, so take the antibiotic at least 2 hours before or 4 to 6 hours after your zinc, and keep zinc and penicillamine at least 1 hour apart.6 Thiazide diuretics raise the zinc you lose in urine, and long-term acid blockers lower what you absorb, so if you've taken one for months, ask the doctor who prescribed it to check your zinc, and don't stop a prescription on your own.611

Pregnancy and breastfeeding. Your needs rise by 3 mg a day in pregnancy and 4 mg while breastfeeding, and the upper limit stays at 40 mg a day (34 mg under age 19).6 Start with food, and if you take a zinc supplement while pregnant or nursing, confirm the dose with your OB.

Children. Children's needs and upper limits are much smaller than adults', so keep a child's everyday zinc within the amounts for their age in the daily-needs table above, and for diarrhea, use the WHO's short course described in the diarrhea section.624

The bottom line

Zinc deficiency: frequently asked questions

References

1. Axe J, Cole W. The 25 Root-Cause Bloodwork Markers That Matter Most. DrAxe.com protocol. 2026. Marker 14, RBC zinc; marker 16, copper-to-zinc ratio.
2. Linus Pauling Institute Micronutrient Information Center. Zinc. Oregon State University. Updated February 2019, reviewed May 2019.
3. Prasad AS, Beck FW, Bao B, Fitzgerald JT, Snell DC, Steinberg JD, et al. Zinc supplementation decreases incidence of infections in the elderly: effect of zinc on generation of cytokines and oxidative stress. Am J Clin Nutr. 2007;85(3):837-44. doi:10.1093/ajcn/85.3.837. PMID:17344507
4. Prasad AS. Discovery of human zinc deficiency: its impact on human health and disease. Adv Nutr. 2013;4(2):176-90. doi:10.3945/an.112.003210. PMID:23493534
5. U.S. Department of Agriculture, Agricultural Research Service. FoodData Central (SR Legacy, 2019): Beef, chuck, arm pot roast, separable lean only, trimmed to 0" fat, choice, cooked, braised (FDC 170615); Beef, ground, 93% lean meat / 7% fat, raw (FDC 173110); Beef, grass-fed, ground, raw (FDC 168608); Bison, ground, grass-fed, cooked (FDC 173847); Lamb, leg, whole (shank and sirloin), separable lean only, trimmed to 1/4" fat, choice, cooked, roasted (FDC 174314); Beef, variety meats and by-products, liver, cooked, pan-fried (FDC 168627); Seeds, pumpkin and squash seed kernels, roasted, without salt (FDC 170557); Seeds, hemp seed, hulled (FDC 170148); Nuts, cashew nuts, raw (FDC 170162); Chickpeas (garbanzo beans, bengal gram), mature seeds, cooked, boiled, without salt (FDC 173757); Lentils, mature seeds, cooked, boiled, without salt (FDC 172421); Seeds, sesame butter, tahini, from roasted and toasted kernels (most common type) (FDC 170189); Egg, whole, cooked, hard-boiled (FDC 173424).
6. Office of Dietary Supplements, National Institutes of Health. Zinc: Fact Sheet for Health Professionals. Updated January 6, 2026.
7. Nävert B, Sandström B, Cederblad A. Reduction of the phytate content of bran by leavening in bread and its effect on zinc absorption in man. Br J Nutr. 1985;53(1):47-53. doi:10.1079/bjn19850009. PMID:2998440
8. Axe J, Cole W. Heal Your Cells. Avery; 2026. Immune protocol, zinc entry (zinc picolinate, citrate or glycinate; 15 to 30 mg a day, avoiding more than 50 mg a day long term; pp. 326-327); phytic acid, sprouting and fermenting (grains section).
9. King JC, Brown KH, Gibson RS, Krebs NF, Lowe NM, Siekmann JH, et al. Biomarkers of Nutrition for Development (BOND)-Zinc Review. J Nutr. 2015;146(4):858S-885S. doi:10.3945/jn.115.220079. PMID:26962190
10. Wessells KR, Brown KH. Estimating the global prevalence of zinc deficiency: results based on zinc availability in national food supplies and the prevalence of stunting. PLoS One. 2012;7(11):e50568. doi:10.1371/journal.pone.0050568. PMID:23209782
11. Ozutemiz AO, Aydin HH, Isler M, Celik HA, Batur Y. Effect of omeprazole on plasma zinc levels after oral zinc administration. Indian J Gastroenterol. 2002;21(6):216-8. PMID:12546170
12. Lin PH, Sermersheim M, Li H, Lee PHU, Steinberg SM, Ma J. Zinc in Wound Healing Modulation. Nutrients. 2017;10(1). doi:10.3390/nu10010016. PMID:29295546
13. Prasad AS, Mantzoros CS, Beck FW, Hess JW, Brewer GJ. Zinc status and serum testosterone levels of healthy adults. Nutrition. 1996;12(5):344-8. doi:10.1016/s0899-9007(96)80058-x. PMID:8875519
14. Sturniolo GC, Di Leo V, Ferronato A, D'Odorico A, D'Incà R. Zinc supplementation tightens "leaky gut" in Crohn's disease. Inflamm Bowel Dis. 2001;7(2):94-8. doi:10.1097/00054725-200105000-00003. PMID:11383597
15. Meydani SN, Barnett JB, Dallal GE, Fine BC, Jacques PF, Leka LS, et al. Serum zinc and pneumonia in nursing home elderly. Am J Clin Nutr. 2007;86(4):1167-73. doi:10.1093/ajcn/86.4.1167. PMID:17921398
16. Heckmann SM, Hujoel P, Habiger S, Friess W, Wichmann M, Heckmann JG, et al. Zinc gluconate in the treatment of dysgeusia--a randomized clinical trial. J Dent Res. 2005;84(1):35-8. doi:10.1177/154405910508400105. PMID:15615872
17. Kumbargere Nagraj S, George RP, Shetty N, Levenson D, Ferraiolo DM, Shrestha A. Interventions for managing taste disturbances. Cochrane Database Syst Rev. 2017;12(12):CD010470. doi:10.1002/14651858.CD010470.pub3. PMID:29260510
18. Wilkinson EA. Oral zinc for arterial and venous leg ulcers. Cochrane Database Syst Rev. 2012;(8):CD001273. doi:10.1002/14651858.CD001273.pub2. PMID:22895918
19. Kil MS, Kim CW, Kim SS. Analysis of serum zinc and copper concentrations in hair loss. Ann Dermatol. 2013;25(4):405-9. doi:10.5021/ad.2013.25.4.405. PMID:24371385
20. Betsy A, Binitha M, Sarita S. Zinc deficiency associated with hypothyroidism: an overlooked cause of severe alopecia. Int J Trichology. 2013;5(1):40-2. doi:10.4103/0974-7753.114714. PMID:23960398
21. Yee BE, Richards P, Sui JY, Marsch AF. Serum zinc levels and efficacy of zinc treatment in acne vulgaris: A systematic review and meta-analysis. Dermatol Ther. 2020;33(6):e14252. doi:10.1111/dth.14252. PMID:32860489
22. Axe J. Skin Care Mistakes That Are Aging Your Skin (and Wrecking Your Hormones). The Dr. Josh Axe Show. 2025. Zinc and copper at 35:25 to 35:55 (37:11 in the episode page transcript); acne cases at 53:56 to 54:33. YouTube: https://www.youtube.com/watch?v=CsKuJ9EWueY
23. Lazzerini M, Wanzira H. Oral zinc for treating diarrhoea in children. Cochrane Database Syst Rev. 2016;12(12):CD005436. doi:10.1002/14651858.CD005436.pub5. PMID:27996088
24. World Health Organization. Guideline on management of pneumonia and diarrhoea in children up to 10 years of age. Geneva: World Health Organization; 2024. ISBN 978-92-4-010341-2. Zinc recommendations: oral zinc as add-on treatment for acute watery and persistent diarrhoea in children up to 10 years; suggested 5 mg dose (conditional recommendation, low-certainty evidence); duration per existing recommendations, 10 to 14 days.
25. Birmingham CL, Goldner EM, Bakan R. Controlled trial of zinc supplementation in anorexia nervosa. Int J Eat Disord. 1994;15(3):251-5. PMID:8199605
26. Swardfager W, Herrmann N, Mazereeuw G, Goldberger K, Harimoto T, Lanctôt KL. Zinc in depression: a meta-analysis. Biol Psychiatry. 2013;74(12):872-8. doi:10.1016/j.biopsych.2013.05.008. PMID:23806573
27. Yosaee S, Clark CCT, Keshtkaran Z, Ashourpour M, Keshani P, Soltani S. Zinc in depression: From development to treatment: A comparative/ dose response meta-analysis of observational studies and randomized controlled trials. Gen Hosp Psychiatry. 2022;74:110-117. doi:10.1016/j.genhosppsych.2020.08.001. PMID:32829928
28. Axe J. Women NEED to Know This Before Getting on HRT. The Dr. Josh Axe Show. 2026. Pumpkin seeds and grass-fed beef for zinc at 27:40 to 28:07 and 33:51 to 34:41. YouTube: https://www.youtube.com/watch?v=rcPa3Wnl_CI
29. Foster M, Chu A, Petocz P, Samman S. Effect of vegetarian diets on zinc status: a systematic review and meta-analysis of studies in humans. J Sci Food Agric. 2013;93(10):2362-71. doi:10.1002/jsfa.6179. PMID:23595983
30. Lopresti AL. The Effects of Psychological and Environmental Stress on Micronutrient Concentrations in the Body: A Review of the Evidence. Adv Nutr. 2020;11(1):103-112. doi:10.1093/advances/nmz082. PMID:31504084
31. Axe J. Top 10 Worst Health Trends (That Everyone Thinks Are Healthy). The Dr. Josh Axe Show. 2026. Deficiencies on vegan and raw diets at 10:29 to 10:54 and 11:34 to 11:55. YouTube: https://www.youtube.com/watch?v=gDmz6u5Vt7Q
32. Siva S, Rubin DT, Gulotta G, Wroblewski K, Pekow J. Zinc Deficiency is Associated with Poor Clinical Outcomes in Patients with Inflammatory Bowel Disease. Inflamm Bowel Dis. 2017;23(1):152-157. doi:10.1097/MIB.0000000000000989. PMID:27930412
33. Duncan A, Yacoubian C, Watson N, Morrison I. The risk of copper deficiency in patients prescribed zinc supplements. J Clin Pathol. 2015;68(9):723-5. doi:10.1136/jclinpath-2014-202837. PMID:26085547
34. Bouvard V, Loomis D, Guyton KZ, Grosse Y, Ghissassi FE, Benbrahim-Tallaa L, et al. Carcinogenicity of consumption of red and processed meat. Lancet Oncol. 2015;16(16):1599-600. doi:10.1016/S1470-2045(15)00444-1. PMID:26514947
35. Axe J. 10 Biblical Superfoods That Can Add Years to Your Life. The Dr. Josh Axe Show, Episode 393. September 28, 2026. Red-meat studies and grain-fed meat at 21:03 (YouTube video 9AnNi1umufc).
36. Axe J. 10 Signs You Have an Iron Deficiency (How to Boost Iron Naturally). The Dr. Josh Axe Show. October 8, 2024. Sprouted and fermented grains and phytic acid at 22:42 (episode page transcript).
37. Axe J. Top 10 Reasons You're Not Healing. The Dr. Josh Axe Show. 2025. Zinc with copper and pumpkin seed butter at 16:12 to 16:57. YouTube: https://www.youtube.com/watch?v=bjU77gf__x4
38. Axe J. Healing Leaky Gut Protocol: The 30-Day System. DrAxe.com protocol. 2026. Supplement stack (zinc carnosine 75 mg twice daily with food).
39. Axe J. Complete Guide to Healing Leaky Gut Naturally. The Dr. Josh Axe Show. 2026. Zinc as the immune and repair mineral and zinc carnosine at 38:40 to 38:56 (38:42 in the episode page transcript). YouTube: https://www.youtube.com/watch?v=5Y4g5CgMDoU
40. Mahmood A, FitzGerald AJ, Marchbank T, Ntatsaki E, Murray D, Ghosh S, et al. Zinc carnosine, a health food supplement that stabilises small bowel integrity and stimulates gut repair processes. Gut. 2007;56(2):168-75. doi:10.1136/gut.2006.099929. PMID:16777920
41. Hemilä H, Fitzgerald JT, Petrus EJ, Prasad A. Zinc Acetate Lozenges May Improve the Recovery Rate of Common Cold Patients: An Individual Patient Data Meta-Analysis. Open Forum Infect Dis. 2017;4(2):ofx059. doi:10.1093/ofid/ofx059. PMID:28480298
42. Nault D, Machingo TA, Shipper AG, Antiporta DA, Hamel C, Nourouzpour S, et al. Zinc for prevention and treatment of the common cold. Cochrane Database Syst Rev. 2024;5(5):CD014914. doi:10.1002/14651858.CD014914.pub2. PMID:38719213
43. Fischer Walker CL, Ezzati M, Black RE. Global and regional child mortality and burden of disease attributable to zinc deficiency. Eur J Clin Nutr. 2009;63(5):591-7. doi:10.1038/ejcn.2008.9. PMID:18270521
44. Cashman MW, Sloan SB. Nutrition and nail disease. Clin Dermatol. 2010;28(4):420-5. doi:10.1016/j.clindermatol.2010.03.037. PMID:20620759
45. 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. Arch Ophthalmol. 2001;119(10):1417-36. doi:10.1001/archopht.119.10.1417. PMID:11594942

Dr. Josh Axe, DC, DNM, CNS

Doctor of Natural Medicine · Founder, DrAxe.com

Dr. Axe is a certified doctor of natural medicine, clinical nutritionist, and multiple New York Times bestselling author. He has spent 20+ years in clinical practice helping people heal at the root cause and founded one of the most-visited natural-health platforms in the world.

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