mineral
Zinc: Forms, How Much Per Day, Iron and Copper
Also known as zinc gluconate, zinc citrate, zinc picolinate, zinc sulfate, zinc acetate, zinc oxide, zinc lozenges
Short answer
Zinc is a mineral the body needs for hundreds of enzymes, protein and DNA synthesis, wound healing and immune function. Labels list elemental zinc. Citrate and gluconate are absorbed similarly, and slightly better than oxide. The adult upper limit is 40 mg a day; 50 mg or more for weeks can lower copper [1].
Last reviewed · 2 sources
What is Zinc?
Zinc is an essential mineral found in some foods, added to others, and sold as a supplement [1]. The body needs it for the activity of hundreds of enzymes and uses it in immune function, protein and DNA synthesis, wound healing, and cell signaling and division [1]. It is also needed for growth during pregnancy, infancy, childhood and adolescence, and for the sense of taste [1]. Most of the body's zinc is stored in muscle and bone [1].
Forms of Zinc you'll see on labels
Zinc gluconate
About 61% absorbed in young adults, similar to zinc citrate [1]. Also used in cold lozenges [1].
Zinc citrate
About 61% absorbed in young adults, similar to zinc gluconate [1].
Zinc oxide
About 50% absorbed, a little less than citrate or gluconate [1].
Zinc sulfate and zinc acetate
Other common supplement forms; zinc acetate is also used in cold lozenges [1].
How much Zinc do adults need?
NIH lists these Recommended Dietary Allowances (RDA) for adults 19+, in mg. Reference values, not a personal recommendation.
| Group | Amount per day |
|---|---|
| Men 19+ | 11 mg |
| Women 19+ | 8 mg |
| Pregnancy 19+ | 11 mg |
| Lactation 19+ | 12 mg |
Upper limit: 40 mg a day for adults 19+, including during pregnancy and lactation, from food and supplements. It does not apply to people taking zinc as medical treatment under a doctor's care [1].
How Zinc appears on a label
The Supplement Facts panel lists elemental zinc, not the weight of the whole compound (such as zinc gluconate) [1]. Amounts are in mg. The Daily Value (DV) used for % DV is 11 mg for adults and children 4 and older [1]. Check cold lozenges, nasal products and some denture creams too, as they can also contain zinc [1].
When to take Zinc
No official source names a best time of day to take zinc or says whether to take it with food. NIH does say that iron supplements of 25 mg or more taken at the same time as zinc can reduce zinc absorption, and gives antibiotic spacing (see below) [1].
What to keep apart from Zinc
Iron supplements
Taking 25 mg or more of iron at the same time as zinc can reduce zinc absorption. The iron in fortified foods does not interfere much [1].
Copper
50 mg or more of zinc a day for weeks can interfere with copper absorption and lead to low copper [1]. The NHS also says high zinc doses reduce copper absorption [2].
Magnesium
Very high zinc doses (142 mg a day) might interfere with magnesium absorption [1].
Phytates (whole grains, beans, nuts)
Phytates bind zinc in the gut and reduce its absorption, so zinc from plant foods is absorbed less than from animal foods [1].
Quinolone and tetracycline antibiotics
Zinc and these antibiotics can block each other's absorption. NIH says to take the antibiotic at least 2 hours before or 4 to 6 hours after zinc [1]. Ask your pharmacist.
Penicillamine
Zinc can reduce its absorption and action; NIH says to take them at least 1 hour apart [1]. Ask your pharmacist.
Thiazide diuretics
These increase zinc loss in urine and can lower blood zinc [1]. Ask your pharmacist.
Foods that contain Zinc
- Oysters
- Beef
- Blue crab
- Fortified breakfast cereals
- Oats
- Pumpkin seeds
- Pork and turkey
- Cheese, milk and yogurt
- Shrimp
- Lentils and beans
Who should ask a doctor or pharmacist first
Talk to a doctor or pharmacist first if you take quinolone or tetracycline antibiotics, penicillamine or thiazide diuretics [1]. Ask too if you have a digestive condition or have had weight-loss surgery, or if you are pregnant or breastfeeding [1]. The NHS advises not taking more than 25 mg of zinc supplements a day unless a doctor advises it [2].
Keep Zinc in a routine that fits
Supin schedules what you take by time of day, reminds you, and tells you when a bottle runs low.
Zinc: questions people ask
NIH says zinc citrate and zinc gluconate are absorbed similarly, at about 61% in young adults, and zinc oxide at about 50% [1]. The NIH fact sheet does not give absorption data for zinc picolinate.
Research is mixed. A 2024 Cochrane review cited by NIH found zinc may shorten colds by about 2 days but makes little or no difference to preventing them, based on low to very low certainty evidence [1].
For quinolone and tetracycline antibiotics, NIH says to take the antibiotic at least 2 hours before or 4 to 6 hours after zinc [1]. Ask your pharmacist about your specific medicine.
Sources
- Zinc: Fact Sheet for Health Professionals — NIH Office of Dietary Supplements
- Others - Vitamins and minerals (Zinc) — NHS
Educational information, not medical advice. The amounts above are official reference values, not a recommendation for you. Check with your doctor or pharmacist before starting or changing supplements, especially if you take medication, are pregnant or have a health condition. Supin sells a subscription, not supplements. Last reviewed .