Zinc

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By Nikola · Precision Nutrition L1 · Updated 5 November 2026

Zinc is an essential mineral that the body uses for DNA synthesis, cell division, protein and carbohydrate metabolism, fertility and normal cognitive function, and it has to come from food or supplements. EFSA sets a population reference intake of 9.4-16.3 mg a day for men and 7.5-12.7 mg for women, depending on how much phytate (from whole grains and pulses) your diet contains. Oysters, red meat, pumpkin seeds, cheese and pulses are the main sources. Zinc lozenges may shorten a cold by about two days, on weak evidence, and do not prevent colds. The EFSA upper limit for adults is 25 mg a day; long-term high doses can cause copper deficiency.

What the research says

• Shorter colds (weak evidence). A 2024 Cochrane review of 34 trials with 8,526 people found that zinc taken once a cold has started may shorten it by about 2.4 days, with low certainty. Mild side effects were about a third more common than with placebo. Trials used 45-300 mg a day, and an older analysis found benefit only above 75 mg (NIH), far over the upper limit, so this is a few-days use only.
• Preventing colds (no clear effect). In the same Cochrane review, taking zinc regularly made little or no difference to the chance of catching a cold.
• Age-related macular degeneration (moderate evidence, specific formula). In the AREDS trial, a formula with 80 mg zinc, antioxidants and 2 mg copper lowered the risk of advanced AMD by 25% over 5 years. The dose is over three times the EFSA upper limit: a decision for an eye doctor.
• At-risk groups. People on plant-based diets, with inflammatory bowel disease or coeliac disease, or with alcohol use disorder more often have low zinc status (NIH); a doctor’s assessment comes first.
• EU-authorised claims. Under Regulation (EU) 432/2012, foods that are at least a source of zinc may say, among other claims, that “Zinc contributes to normal DNA synthesis”, “to normal cognitive function”, “to normal fertility and reproduction”, “to normal acid-base metabolism”, “to normal carbohydrate metabolism” and “to normal macronutrient metabolism”. These describe zinc’s normal role, not a benefit of extra zinc when you already get enough.

Not shown: that zinc prevents colds or infections in well-nourished adults, or that long-term high doses help healthy people.

Dose and forms

Group	EFSA PRI, mg a day	EFSA upper limit (UL)	For reference: US RDA
Men	9.4-16.3 (rises with phytate intake)	25 mg	11 mg
Women	7.5-12.7 (rises with phytate intake)	25 mg	8 mg
Pregnancy	PRI for women + 1.6 mg	see note	11 mg
Breastfeeding	PRI for women + 2.9 mg	see note	12 mg
Children and teenagers (7 months-17 years)	2.9-14.2, by age	lower than adults, by age	3-11 mg

Source: EFSA NDA Panel (2014); EFSA overview of upper intake levels (version 11, 2025), 25 mg a day for adults; NIH ODS for the US RDA. EFSA calculated adult PRIs for phytate intakes of 300-1,200 mg a day: the more whole grains and pulses you eat, the more zinc you need. We could not confirm a separate EFSA upper limit for pregnancy and breastfeeding, so ask your doctor first. The NHS advises no more than 25 mg a day from supplements unless a doctor says otherwise.

Forms. Gluconate, sulfate, acetate, citrate and oxide are common. Zinc citrate and gluconate were absorbed at about 61% and oxide at about 50% in young adults (NIH). Compare the elemental zinc on the label with the 25 mg limit. Use cold lozenges only for the few days of a cold and stop if they make you feel sick.

Food sources

Food	Zinc, 100 g	Portion	Zinc per portion
Oysters, eastern, farmed, raw	37.9 mg	6 medium, 84 g	31.8 mg
Ground beef, 80% lean, raw	4.18 mg	113 g raw	4.7 mg
Pumpkin seeds, dried	7.81 mg	28 g	2.2 mg
Chickpeas, boiled	1.53 mg	1 cup, 164 g	2.5 mg
Lentils, boiled	1.27 mg	1 cup, 198 g	2.5 mg
Cashews, raw	5.78 mg	28 g	1.6 mg
Feta cheese	2.88 mg	1 piece, 38 g	1.1 mg
Oats, dry	3.64 mg	27 g	1.0 mg
Sesame seeds, whole	7.75 mg	1 tbsp, 9 g	0.7 mg

Source: USDA FoodData Central, SR Legacy, checked 5 November 2026: oysters FDC 175172, ground beef FDC 174036, pumpkin seeds FDC 170556, chickpeas FDC 173757, lentils FDC 172421, cashews FDC 170162, feta FDC 173420, oats FDC 173904, sesame seeds FDC 170150. Values per portion are calculated from USDA household measures and rounded.

Six oysters exceed the upper limit in one go, while an ordinary day gets close to the EFSA range: 28 g of pumpkin seeds, a cup of chickpeas or lentils, a small bowl of oats, a piece of feta and 113 g of beef add up to about 11.5 mg; an egg adds about 0.6 mg (NIH). Phytate in plant foods binds zinc, so absorption ranges from about 5% to more than 50% depending on the diet; the NIH suggests soaking beans, grains and seeds and eating fermented foods. Eggs, tahini and cashews are easy extras.

Side effects and interactions

• Too much at once. High doses can cause nausea, vomiting, loss of appetite, stomach upset, dizziness and headaches (NIH).
• Copper deficiency. 50 mg or more a day for weeks can interfere with copper absorption, lower immune function and reduce HDL cholesterol (NIH); the NHS warns this can lead to anaemia and weakened bones. Overused zinc denture creams have caused copper deficiency with nerve damage.
• Nasal zinc. In 2009 the FDA warned, after more than 130 reports, that some zinc nasal cold products may cause a loss of smell that may be permanent.
• Medicines. Take quinolone or tetracycline antibiotics at least 2 hours before or 4-6 hours after zinc, and separate penicillamine from zinc by at least 1 hour. Thiazide diuretics increase zinc loss in urine (NIH).
• Iron. Iron supplements of 25 mg or more taken with zinc can reduce zinc absorption; iron in fortified foods does not (NIH).

Who should avoid it

• Anyone who takes zinc daily “just in case” while eating well: no benefit is shown, and zinc-rich food leaves little margin to 25 mg.
• People on the medicines above, unless a doctor or pharmacist has set the timing.
• Pregnant or breastfeeding women, children and people with bowel disease, unless a doctor advises it.
• Anyone considering high-dose zinc for the eyes, without an eye doctor.

How to choose a good product

• Read elemental zinc per serving and add up everything you take, including multivitamins and lozenges.
• For daily use, stay near your EFSA reference intake, not near 25 mg.
• Look for independent testing. Seals from U.S. Pharmacopeia, NSF International or ConsumerLab.com show a product was tested for its contents and harmful contaminants; the NIH stresses they do not prove safety or effect.

We do not recommend brands or link to shops.

FAQ

Does zinc help with a cold?

It may shorten a cold by about two days if you start soon after symptoms begin, according to a 2024 Cochrane review, but the certainty is low. Daily zinc does not clearly prevent colds, and mild side effects are more common than with placebo.

How much zinc should I take a day?

Most adults can get the EFSA reference intake (7.5-12.7 mg for women, 9.4-16.3 mg for men) from food. The EFSA upper limit for adults is 25 mg a day, and the NHS advises no more than 25 mg from supplements unless a doctor says so.

What is the best form of zinc?

In studies cited by the NIH, zinc citrate and gluconate were absorbed at about 61% and zinc oxide at about 50%. The amount of elemental zinc on the label matters more than the form.

Related entries and articles

• Pumpkin seeds, cashews and sesame seeds
• Chickpeas and lentils
• Ground beef and feta cheese
• Iron, magnesium and vitamin A
• Zinc-rich foods: best sources and how much you need
• Pumpkin seeds: benefits and how many to eat a day
• Recipe: roasted pumpkin with chickpeas, tahini and pomegranate
• Recipe: warm lentil salad with roasted carrots and feta

Sources

1. NIH Office of Dietary Supplements: Zinc, Fact Sheet for Health Professionals. ods.od.nih.gov
2. EFSA NDA Panel (2014). Scientific Opinion on Dietary Reference Values for zinc. EFSA Journal 12(10):3844. efsa.europa.eu
3. EFSA: Overview on Tolerable Upper Intake Levels as derived by the SCF and the EFSA NDA Panel, version 11 (2025). efsa.europa.eu
4. Commission Regulation (EU) No 432/2012, Annex – authorised health claims (zinc). eur-lex.europa.eu
5. Nault D, et al. (2024). Zinc for prevention and treatment of the common cold. Cochrane Database of Systematic Reviews, CD014914, via Europe PMC. europepmc.org
6. NHS: Vitamins and minerals – Others (zinc). nhs.uk
7. U.S. FDA consumer update on zinc nasal products and loss of smell, 16 June 2009 (archived). webarchive.library.unt.edu
8. NIH Office of Dietary Supplements: Dietary Supplements – What You Need to Know. ods.od.nih.gov
9. USDA FoodData Central, SR Legacy records for the nine foods in the table (FDC IDs listed under it). fdc.nal.usda.gov

This page is for information only and is not medical or dietary advice.