Zinc is a mineral your body needs for growth, wound healing, immunity and the senses of taste and smell. Most people get enough from food, but some groups are at higher risk of falling short, and too much zinc from supplements causes problems of its own. This guide covers daily needs, food sources, deficiency signs, safe limits and medicine interactions, based on the NIH Office of Dietary Supplements consumer fact sheet.
How Much Zinc Do You Need Each Day?
The NIH gives these recommended daily amounts:
- Children 1 to 3 years: 3 mg
- Children 4 to 8 years: 5 mg
- Children 9 to 13 years: 8 mg
- Teen boys 14 to 18 years: 11 mg; teen girls 14 to 18 years: 9 mg
- Adult men: 11 mg; adult women: 8 mg
- Pregnant women: 11 mg (12 mg for pregnant teens)
- Breastfeeding women: 12 mg (13 mg for breastfeeding teens)
Best Food Sources of Zinc
Beans and whole grains contain phytates, which reduce zinc absorption. This is one reason vegetarians and vegans may need to pay extra attention to zinc intake.
- Oysters, which have very high amounts of zinc
- Meat, fish, poultry, and seafood such as crab and lobster
- Fortified breakfast cereals
- Beans, nuts, whole grains, eggs and dairy, which provide some zinc
Signs of Zinc Deficiency
The NIH lists these possible signs. Many of them can also have other causes, so a doctor should confirm the reason.
- Diarrhea, slow growth and loss of appetite in infants and children
- Hair loss and frequent infections in older children
- Loss of taste and smell at any age
- Delayed wound healing and problems with thinking and memory in older adults
Who May Have Trouble Getting Enough Zinc?
- People who have had gastrointestinal surgery, such as weight loss surgery, or who have ulcerative colitis or Crohn disease
- Vegetarians and vegans
- Pregnant or breastfeeding women
- Older breastfed infants (over 6 months), since breast milk does not provide enough zinc for them
- Children with sickle cell disease
- People with alcohol use disorder
The NIH also notes that most people in the United States get enough zinc from the foods they eat.
How Much Zinc Is Too Much?
The upper limit for adults is 40 mg a day from all sources. For teens 14 to 18 years it is 34 mg. This limit does not apply to zinc a doctor prescribes for medical reasons.
Too much zinc can cause nausea, dizziness, headaches, upset stomach, vomiting and loss of appetite. Taking high amounts for a long time can lower immunity, lower HDL cholesterol and reduce copper levels. Large amounts of zinc-containing denture cream have also been linked to copper deficiency with nerve problems.
Zinc and Medicine Interactions
- Quinolone and tetracycline antibiotics: take the antibiotic at least 2 hours before, or 4 to 6 hours after, a zinc supplement.
- Penicillamine: take zinc and penicillamine at least 1 hour apart.
- Thiazide diuretics such as chlorthalidone and hydrochlorothiazide increase zinc lost in urine, and long-term use might lower zinc levels.
When to See a Doctor
- You have lost your sense of taste or smell with no clear reason
- Wounds are slow to heal or you get frequent infections
- You follow a vegan diet or have a digestive condition affecting absorption
- You are thinking about a high-dose zinc supplement
Frequently Asked Questions
How much zinc do adults need per day?
Adult men need 11 mg a day and adult women need 8 mg a day, according to the NIH.
Which foods are rich in zinc?
Oysters are the richest source. Meat, fish, poultry, crab, lobster and fortified cereals are also good sources, with beans, nuts, whole grains, eggs and dairy providing some.
What is the upper limit for zinc?
For adults the upper limit is 40 mg a day from all sources, unless a doctor prescribes more for a medical reason.
What are the signs of too much zinc?
Nausea, dizziness, headaches, upset stomach, vomiting and loss of appetite. Long-term excess can lower immunity and copper levels.
Can zinc supplements interfere with antibiotics?
Yes. Quinolone and tetracycline antibiotics should be taken at least 2 hours before, or 4 to 6 hours after, a zinc supplement.
Related reading: Iron Deficiency guide | Calcium daily needs and supplements | Vitamin B12 deficiency guide
Sources
- NIH Office of Dietary Supplements: Zinc fact sheet for consumers
- NIH Office of Dietary Supplements: Multivitamin/mineral supplements fact sheet
Medical disclaimer: this article is for general information and does not replace advice from a qualified doctor. Do not start, stop or change any supplement or medicine without medical advice.