- Zinc plays an important part in immune health, digestion, wound healing, and taste and smell.
- Exceeding the recommended daily allowance could cause cramps, vomiting, and other side effects.
- A varied diet usually provides enough zinc, but people with zinc deficiencies may need supplements.
Zinc is an essential mineral for your health. It plays a role in:
- Digestion and metabolism
- Wound healing
- Immune health
- Your sense of taste and smell
Of all the trace minerals, only iron is found in higher concentrations in the body.
Yet even though zinc is important for your health, you can still get too much of it.
"The tolerable upper intake level (UL) for zinc, meaning the highest recommended daily amount, is 40 mg per day," says Dr. Jeffrey Gladd, an integrative medicine physician and chief medical officer at Fullscript.
Read on to learn the signs of a zinc overdose, how to get treatment, and what you can do to get the recommended daily amount of zinc.
Signs of a zinc overdose
A zinc overdose can involve different symptoms, depending on whether it's acute or chronic.
An acute overdose means you ingest a large amount of zinc in a short period of time.
Symptoms of an acute overdose usually won't appear until you ingest one to two grams of zinc, and Gladd says you don't need to worry about getting too much zinc from your diet.
A zinc overdose typically happens as a result of:
- Taking too many zinc supplements: If your daily dose of zinc supplements adds up to one or more grams of zinc, you could experience symptoms of an acute overdose. Always check with your doctor before taking supplements and make sure to follow the dosing guidelines on the bottle.
- Occupational exposure: If you weld or solder metal, inhaling the fumes produced could put you at risk of zinc overexposure. This type of zinc exposure, called metal fume fever, produces flu-like symptoms, such as fever, cough, aching muscles, and fatigue.
- Swallowing pennies: Coins are the most common foreign object ingested by children. Penny produced after 1982 can present an additional danger when swallowed, as they're composed mostly of zinc.
Symptoms of acute zinc overdose might include:
- Abdominal cramps
- Loss of appetite
A zinc overdose can be life threatening. If you suspect you may have consumed too much zinc and have symptoms of an overdose, you'll want to contact 911 or a poison control center for emergency medical support, Gladd says.
The treatment for oral zinc overdose may include:
- Medications to treat nausea and vomiting.
- Proton pump inhibitors and H2 blockers to relieve abdominal pain.
- Whole bowel irrigation, which removes excess zinc by clearing your bowels.
- Chelation, which uses medications to remove zinc from your bloodstream. These are typically used in more severe cases that may also require hospitalization.
A chronic overdose means you've regularly consumed too much zinc over a longer period of time.
Chronic zinc overdose can occur when you ingest anywhere from 150-450 milligrams (mg) of zinc per day.
This generally happens as a result of taking too many zinc supplements, but using large amounts of zinc-containing denture creams can also expose you to excess zinc.
The symptoms of chronic excess zinc can affect your whole body and may include:
- Copper deficiency: "Taking high doses of zinc over a long period of time can lead to a copper deficiency, which can contribute to health concerns such as anemia and low white blood cell count," Gladd says. Additionally, copper deficiency may have neurological impacts including neuropathy, issues with coordination, and difficulty walking.
- Reduced high density lipoproteins: A 2015 review of studies on zinc found that for people with type 2 diabetes or kidney failure, zinc supplementation may raise HDL, or "good" cholesterol. However, in healthy people, extra zinc had the opposite effect — supplements appeared to decrease the study participants' HDL.
- Reduced immune function: Excess zinc affects the number of cells present in your immune system and how they function. Impaired immune function can leave you more susceptible to infections, colds, and inflammatory diseases.
- Altered sense of taste: Zinc is required for your sense of taste and smell — in fact, research has explored the benefits of zinc supplements for treating taste disorders. In excess amounts, though, zinc can create a metallic taste in your mouth.
If you've taken more than the daily recommended amount of zinc for more than a few days and notice any of the above signs and symptoms, you should stop taking any supplemental zinc and check in with your doctor. Depending on how much zinc you've taken, and for how long, they may recommend treatment.
How much zinc should you have per day?
If you eat a balanced diet that includes a variety of zinc-containing foods, you likely don't need to supplement with extra zinc, Gladd says. This means, of course, you won't run the risk of getting too much zinc.
Foods that contain plenty of zinc include:
- Meats like fish, poultry, beef, and pork
- Whole grains
- Nuts and seeds
- Fortified breakfast cereals
However, certain groups of people are more likely to have a zinc deficiency, including:
- Vegetarians: Eating a vegetarian diet could lead to zinc deficiency, since meat tends to have the most bioavailable amounts of zinc. Legumes and whole grains, on the other hand, can inhibit zinc absorption.
- Pregnant and lactating people: Your zinc needs increase during pregnancy and lactation. The Food and Nutrition Board recommends pregnant and lactating people consume an additional 3 g and 4 g of zinc, respectively, each day.
- People with inflammatory bowel disease: Conditions like Crohn's disease or ulcerative colitis can hinder your absorption of zinc.
- People with alcohol use disorder: Long-term heavy alcohol consumption can affect your body's ability to absorb zinc as it should.
- People with sickle cell disease: Studies show that people who have sickle cell disease have a high risk of zinc insufficiency due to impaired absorption of zinc in the kidneys.
- Older infants who are exclusively breastfed: Breast milk alone doesn't meet an infant's zinc requirement once they reach the age of 6 months. Infants older than 7 months need to consume foods or formula that contain zinc in addition to breast milk, according to the Centers for Disease Control and Prevention (CDC).
"If you're concerned about zinc levels, the best option is to get a zinc blood test. They are relatively inexpensive and allow you to get quick, accurate results," says Daniel Powers, herbal medicine expert and founder of the Botanical Institute.
Keep in mind it's always important to ask a healthcare professional before taking any supplement — especially zinc, which you can easily overconsume.
The FDA doesn't regulate supplements, so it's important to check with your doctor if you're unsure about how much of any supplement to take. Opting for supplements that have undergone third-party testing can also help you ensure you get the supplement you want, in the advertised amount.
If you choose to supplement, keep in mind that experts recommend consuming no more than the recommended daily allowance (RDA) of zinc:
- For men: 11 mg per day
- For women: 8 mg per day
- During pregnancy: 11 mg per day
- When lactating: 12 mg per day
Zinc requirements for children and teens range from 2 mg to 11 mg per day, depending on age. If you think your child may not get enough zinc from their diet, it's best to ask your pediatrician about the correct dose.
Although you need zinc to maintain good health, you can take too much — and excess zinc can have serious health consequences. If you've taken more than the daily recommended dose of zinc, you should get medical attention right away.
In most cases, a varied diet will provide enough zinc, and many people don't need to supplement. However, if you eat a limited diet, are pregnant or lactating, or have a health condition that affects zinc absorption, you may have a higher risk of zinc deficiency.
Your doctor or another healthcare professional can offer more guidance on how much zinc you should take for optimal health.