How Much Zinc Per Day? RDA, Upper Limit and When to Take It

Most adults need 8 to 11 mg of zinc per day: 11 mg for men and 8 mg for women, with 11 to 12 mg during pregnancy and 12 to 13 mg while breastfeeding, and the upper limit for adults is 40 mg a day from food and supplements combined (NIH ODS: Zinc). Below: the full table by age, what the limit counts, food sources, timing and side effects.

It is educational, not medical advice.

Key Takeaways

• The adult RDA is 11 mg a day for men and 8 mg for women. Pregnancy adds 3 mg and breastfeeding adds 4 mg over the nonpregnant amount (NIH ODS: Zinc).
• The adult upper limit is 40 mg a day, and it counts zinc from food and supplements together. It is based on effects on copper status (NIH ODS: Zinc).
• Supplement Facts panels list elemental zinc, not the weight of the whole zinc compound, so compare products by that number.
• Three ounces of farmed raw Eastern oysters supply 32 mg; a 3 oz serving of roasted bottom sirloin supplies 3.8 mg.
• Doses of 50 mg or more for weeks can interfere with copper absorption, lower immune function and lower HDL cholesterol (NIH ODS: Zinc).
• Take quinolone or tetracycline antibiotics at least 2 hours before or 4 to 6 hours after a zinc supplement.

How Much Zinc Per Day: The RDA by Age

Zinc plays a role in immune function, protein and DNA synthesis, wound repair, cell signaling and cell division, and it is involved in the sense of taste (NIH ODS: Zinc).

Age	Male	Female	Pregnancy	Breastfeeding
0 to 6 months*	2 mg	2 mg
7 to 12 months	3 mg	3 mg
1 to 3 years	3 mg	3 mg
4 to 8 years	5 mg	5 mg
9 to 13 years	8 mg	8 mg
14 to 18 years	11 mg	9 mg	12 mg	13 mg
19 years and older	11 mg	8 mg	11 mg	12 mg

*The value for infants up to 6 months is an Adequate Intake, set at the average intake of healthy breastfed infants. Source: NIH ODS: Zinc.

ODS reports average daily intakes from food of 13 mg for men and 9.2 mg for women, rising to 16.4 mg and 12.6 mg when supplements are counted. Even so, about 15 percent of adults 19 and older, and 20.9 percent of girls aged 14 to 18, take in less than the Estimated Average Requirement (NIH ODS: Zinc). For amounts for women over 40, 50 and 60, see our guide to zinc for women, and for what zinc does in the body, see zinc benefits.

The 40 mg Upper Limit and What It Counts

For zinc, the Tolerable Upper Intake Level (UL) counts food and supplements together, and it was set based on how zinc affects copper status. ODS notes that the ULs do not apply to people who receive zinc from a clinician for a medical reason; they should stay under that clinician's care (NIH ODS: Zinc).

Age	Upper limit (all sources)
0 to 6 months	4 mg
7 to 12 months	5 mg
1 to 3 years	7 mg
4 to 8 years	12 mg
9 to 13 years	23 mg
14 to 18 years (including pregnancy and breastfeeding)	34 mg
19 years and older (including pregnancy and breastfeeding)	40 mg

The upper limits are the same for males and females. Because food counts, add up every supplement label you take plus a rough estimate of what you eat.

Elemental Zinc vs Compound Weight

Zinc in supplements is bound to something else, such as sulfate, acetate, gluconate or glycine, and the whole compound weighs more than the zinc inside it. The Supplement Facts panel declares the amount of elemental zinc, not the weight of the entire zinc compound (NIH ODS: Zinc). So a label that reads 10 mg zinc as zinc bisglycinate gives 10 mg of zinc to count toward the RDA and the UL.

Forms also differ in how much of that zinc is absorbed. ODS reports absorption of about 61 percent from zinc citrate or zinc gluconate and 50 percent from zinc oxide in young adults (NIH ODS: Zinc). In one small study of 12 women, a single dose of zinc bisglycinate gave 43 percent more zinc in the blood than the same dose as gluconate (Gandia et al., 2007). Our guide to zinc picolinate vs bisglycinate vs gluconate walks through the form studies, and the zinc bisglycinate ingredient page explains the chelated form we use.

Food Sources of Zinc

Oysters top the ODS food table by a wide margin. The Daily Value on food labels is 11 mg for adults and children 4 and older. These amounts come from the ODS food table (NIH ODS: Zinc).

Food and serving	Zinc (mg)	Percent DV
Oysters, Eastern, farmed, raw, 3 oz	32	291
Oysters, Pacific, cooked, 3 oz	28.2	256
Beef, bottom sirloin, roasted, 3 oz	3.8	35
Blue crab, cooked, 3 oz	3.2	29
Breakfast cereal fortified with 25 percent of the DV, 1 serving	2.8	25
Oats, unenriched, cooked, 1 cup	2.3	21
Pumpkin seeds, roasted, 1 oz	2.2	20
Cheddar cheese, 1.5 oz	1.5	14
Lentils, boiled, 1/2 cup	1.3	12
Egg, 1 large	0.6	5

Plant foods such as whole grains and legumes contain phytates, which bind zinc and inhibit its absorption, so the zinc in vegetarian diets is often less available than the zinc in diets that include meat (NIH ODS: Zinc). See magnesium and zinc together for how the two minerals fit together.

For a ranked list of 26 foods with NIH values per serving, plus vegan sources and a sample day, see our guide to foods high in zinc.

Who Is Most Likely to Fall Short

ODS lists these groups as most likely to have low zinc status (NIH ODS: Zinc):

• People with gastrointestinal disorders such as inflammatory bowel disease, or who have had bariatric surgery that involves removing part of the gut
• People with newly diagnosed celiac disease
• People who follow vegetarian or vegan diets
• Pregnant and breastfeeding women
• Older infants who are exclusively breastfed, since breast milk alone does not meet the zinc requirement after 6 months
• Children with sickle cell disease
• People with alcohol use disorder; ODS notes low zinc status in 30 to 50 percent of this group

Best Time to Take Zinc

The ODS fact sheet does not name a best time of day for zinc. What it does give is spacing advice for a few situations (NIH ODS: Zinc):

• Iron supplements: taking 25 mg or more of elemental iron at the same time as zinc can lower zinc absorption and plasma zinc. Iron added to enriched or fortified foods does not significantly interfere.
• Quinolone and tetracycline antibiotics: take the antibiotic at least 2 hours before or 4 to 6 hours after the zinc.
• Penicillamine: take zinc and penicillamine at least 1 hour apart.

With or without food: small studies show a meal slows and modestly lowers zinc absorption. In 10 people given 45 mg of zinc as gluconate, taking it with breakfast delayed absorption and lowered peak blood zinc by about 31 percent and total absorption by about 28 percent compared with an empty stomach; 2 hours after the meal, absorption was back to normal (Nève et al., 1992). In 4 adults, a meal reduced the fraction absorbed from 3 and 5 mg doses of zinc compared with 1 mg (Sian et al., 1993). Taking zinc between meals may absorb a little better, while taking it with food is a reasonable trade if an empty stomach causes nausea.

ODS lists nausea and gastric distress as signs of high zinc intake. If a zinc product upsets your stomach, check your daily total against the upper limit and ask a pharmacist how to take it.

Zinc Side Effects and Signs of Too Much

Zinc from food rarely reaches levels that cause problems. ODS describes these effects from supplements and other concentrated sources (NIH ODS: Zinc):

• Short term: high intakes can cause nausea, dizziness, headaches, gastric distress, vomiting and loss of appetite.
• Weeks of 50 mg or more: can inhibit copper absorption, which can lead to low copper status, and can reduce immune function and lower HDL cholesterol.
• Very high doses: 142 mg a day from supplements might interfere with magnesium absorption.
• Denture creams: some contain 17 to 34 mg of zinc per gram. Used as directed (0.5 to 1.5 g a day) they are not a concern, but chronic overuse has been linked to zinc toxicity, copper deficiency, neurological symptoms including sensory ataxia and myelopathy, and anemia.

Copper is the main reason the upper limit sits at 40 mg, below the 50 mg level where ODS describes effects on copper.

Zinc and Medicines

ODS names three types of medicine that interact with zinc (NIH ODS: Zinc):

Medicine	What happens	ODS spacing advice
Quinolone and tetracycline antibiotics	Zinc and the antibiotic can each block the other's absorption	Antibiotic at least 2 hours before or 4 to 6 hours after zinc
Penicillamine	Zinc reduces its absorption and action	At least 1 hour apart
Thiazide diuretics (for example chlorthalidone and hydrochlorothiazide)	Increase zinc loss in urine and lower serum zinc	No spacing given; talk with your prescriber

What the Research on Zinc Lozenges Measured

ODS describes the cold research as mixed. A 2021 review of 28 trials with 5,446 participants found that zinc appears to shorten how long cold symptoms last, with mixed effects on how severe they are. A 2024 Cochrane review of 34 trials with 8,526 participants found that zinc may shorten symptoms by about 2 days in people who already have a cold and appears to make little to no difference to the chance of catching one; the certainty of that evidence was rated low to very low (NIH ODS: Zinc). Some lozenge doses ODS describes topped 75 mg a day, far above the 40 mg adult limit, so these studies are not a guide to daily intake.

Coming Soon From Synchronicity

Our Vitamin D Cofactor Capsules will give 10 mg of zinc as zinc bisglycinate per 2 capsules, along with magnesium 100 mg (as magnesium bisglycinate) and boron 3 mg (as boron glycinate). They are not on sale yet. Pre-order on the product page to join the waitlist; no payment is taken.

In plain numbers, 10 mg is 1 mg under the 11 mg RDA for adult men and 2 mg over the 8 mg RDA for adult women. It is one quarter of the 40 mg adult upper limit, which leaves 30 mg for food and anything else you take. Added to the average food intakes ODS reports, it comes to about 23 mg a day for men (13 mg plus 10 mg) and about 19 mg for women (9.2 mg plus 10 mg), both well under 40 mg. Add any multivitamin or other zinc product to that total.

The capsules are made to pair with our Vitamin D3 + K2 Drops, which are available now, with vegan vitamin D3 from lichen and vitamin K2 as MK-4 and MK-7. See our vitamin D3 page, and to learn why these nutrients are grouped, read vitamin D and magnesium and boron benefits.

Safety Note

Talk with a clinician before taking zinc if you are pregnant or breastfeeding, take antibiotics, penicillamine, a thiazide diuretic or iron supplements of 25 mg or more, or have a gut condition that affects absorption. Keep your total at or under the upper limit for your age unless a clinician advises otherwise, and do not give adult products to children, whose limits are much lower.

Frequently Asked Questions

How much zinc should a woman take per day?

The RDA for women 19 and older is 8 mg a day, rising to 11 mg in pregnancy and 12 mg while breastfeeding. For girls aged 14 to 18 it is 9 mg, or 12 mg in pregnancy and 13 mg while breastfeeding (NIH ODS: Zinc).

Is 50 mg of zinc a day too much?

It is above the 40 mg adult upper limit. ODS reports that 50 mg or more taken for weeks can inhibit copper absorption, reduce immune function and lower HDL cholesterol. Only take amounts above the upper limit under a clinician's care.

Is 10 mg of zinc a day enough?

From a supplement, 10 mg is close to the adult RDA on its own: just under the 11 mg for men and above the 8 mg for women. Most people also get zinc from food, so total intake is usually higher.

Does the 40 mg upper limit include zinc from food?

Yes. The zinc UL counts food and supplements together, unlike magnesium, whose limit covers supplements and medicines only.

What are the side effects of zinc?

At high intakes, ODS lists nausea, dizziness, headaches, gastric distress, vomiting and loss of appetite. Long term intake of 50 mg or more can lower copper status.

Can you take zinc and magnesium together?

Yes, at normal amounts. ODS notes that only very high zinc doses, 142 mg a day, might interfere with magnesium absorption. Our guide to magnesium and zinc together covers this in more detail.

Sources

• NIH Office of Dietary Supplements. Zinc: Fact Sheet for Health Professionals. Updated January 6, 2026. ODS
• NIH Office of Dietary Supplements. Zinc: Fact Sheet for Consumers. Updated October 4, 2022. ODS
• Nève J, et al. 1992. Absorption and metabolism of oral zinc gluconate in humans in fasting state, during, and after a meal. Biological Trace Element Research. PubMed
• Sian L, et al. 1993. Influence of a meal and incremental doses of zinc on changes in zinc absorption. American Journal of Clinical Nutrition. PubMed
• Gandia P et al., 2007. Single-dose comparison of zinc bisglycinate and zinc gluconate in 12 healthy women. International Journal for Vitamin and Nutrition Research. PubMed

These statements have not been evaluated by the Food and Drug Administration. This content is for education and is not medical advice. Our products are not intended to diagnose, treat, cure or prevent any disease. Talk with a healthcare provider before starting a new supplement if you are pregnant, breastfeeding or taking medication.