Zinc is an essential mineral involved in over 100 chemical reactions in your body. It’s needed for growth, DNA synthesis and typical taste perception. It also supports wound healing, immune function and reproductive health. Health authorities have set the tolerable upper consumption level (UL) for zinc at 40 mg per day for adults. The UL is the greatest recommended daily amount of a nutrient. For many people, this quantity is unlikely to cause negative side effects.
Food sources high in zinc include red meat, poultry, seafood, whole grains and fortified cereals. Oysters consist of the highest amount, with approximately 493% of the daily value in a 3-ounce (85-gram) serving.
Although some foods can offer amounts well above the UL, there are no reported cases of zinc poisoning from naturally taking place zinc in food.
Nevertheless, zinc poisoning can take place from dietary supplements, consisting of multivitamins, or due to unintentional consumption of zinc-containing household products.
Here are the 7 most common symptoms and signs of zinc overdose.
1. Nausea and Vomiting
Nausea and vomiting are commonly reported side effects of zinc toxicity.
An evaluation of 17 studies on the efficiency of zinc supplements for treating the common cold discovered that zinc may lower the duration of a cold, but adverse effects were common. In fact, 46% of study individuals reported nausea.
Doses greater than 225 mg are emetic, which indicates that vomiting is likely and can take place quickly. In one case, serious nausea and throwing up started simply 30 minutes after a single zinc dose of 570 mg.
However, vomiting can happen at lower doses too. In one six-week research study in 47 healthy individuals taking 150 mg of zinc each day, over half experienced nausea and vomiting.
Although throwing up may assist rid the body of poisonous quantities of zinc, it may not be enough to prevent more complications.
If you have consumed hazardous quantities of zinc, seek medical assistance right now.
2. Stomach Pain and Diarrhea
Usually, stomach pain and diarrhea take place in conjunction with nausea and vomiting.
In one evaluation of 17 studies on zinc supplements and the cold, approximately 40% of individuals reported abdominal discomfort and diarrhea.
Although less common, gut irritation and gastrointestinal bleeding have also been reported.
In one case study, a specific skilled digestive bleeding after taking 220 mg of zinc sulfate twice daily for the treatment of acne.
Furthermore, concentrations of zinc chloride greater than 20% are understood to cause comprehensive corrosive damage to the gastrointestinal tract.
Zinc chloride is not used in dietary supplements, however poisoning can happen from accidental consumption of home products. Adhesives, sealants, soldering fluxes, cleaning up chemicals and wood finishing items all contain zinc chloride.
3. Flu-Like Symptoms
Taking more zinc than the established UL may trigger flu-like symptoms, such as fever, chills, cough, headache and fatigue.
These signs take place in numerous conditions, including other mineral toxicities. Hence, diagnosing zinc toxicity can be tough.
Your doctor might need your detailed medical and dietary history, in addition to blood tests, for a presumed mineral toxicity.
If you’re taking supplements, make certain to divulge these to your healthcare provider.
4. Low “Good” HDL Cholesterol
” Good” HDL cholesterol decreases your threat of heart disease by clearing cholesterol from your cells, therefore avoiding the accumulation of artery-clogging plaque.
For adults, health authorities recommend an HDL greater than 40 mg/dL. Lower levels put you at a greater threat of heart disease.
A review of a number of studies on zinc and cholesterol levels recommends that supplementing with more than 50 mg of zinc each day may lower your “good” HDL levels and not have any effect on your “bad” LDL cholesterol.
The evaluation likewise mentions that doses of 30 mg of zinc per day– lower than the UL for zinc– had no impacts on HDL when considered up to 14 weeks.
While several aspects impact cholesterol levels, these findings are something to think about if you take zinc supplements routinely.
5. Changes in Your Taste
Zinc is very important for your sense of taste. In fact, zinc deficiency can lead to a condition called hypogeusia, a dysfunction in your ability to taste.
Remarkably, zinc in excess of the recommended levels may also trigger taste changes, consisting of a bad or metal taste in your mouth.
Typically, this symptom is reported in research studies examining zinc lozenges (cough drops) or liquid supplements for treating the cold.
While some research studies report advantageous outcomes, the doses utilized are frequently well above the UL of 40 mg each day, and negative impacts are common.
For instance, 14% of individuals in a one-week study experienced taste distortion after liquifying 25-mg zinc tablets in their mouths every 2 hours while awake.
In another research study using a liquid supplement, 53% of participants reported a metallic taste. However, it’s unclear the length of time these symptoms last.
If you’re utilizing zinc lozenges or liquid supplements, know that these signs may take place even if the product is taken as directed.
6. Copper Deficiency
Zinc and copper contend for absorption in your small intestine.
Doses of zinc above the established UL can interfere with your body’s ability to soak up copper. With time, this can cause copper deficiency.
Like zinc, copper is an essential mineral. It helps in iron absorption and metabolism, making it required for red blood cell formation. It likewise plays a role in white blood cell formation.
Red blood cells transport oxygen through your body, while white blood cells are key players in your immune function.
Zinc-induced copper deficiency is associated with several blood disorders:
- Iron deficiency anemia: A lack of healthy red blood cells due to insufficient quantities of iron in your body.
- Sideroblastic anemia: A lack of healthy red blood cells due to an inability to metabolize iron appropriately.
- Neutropenia: A lack of healthy white blood cells due to a disruption in their formation.
If you have copper deficiency, do not blend your copper supplements with zinc.
7. Frequent Infections
Although zinc plays a crucial role in immune system function, too much zinc can suppress your immune response.
This is normally a side effect of anemias and neutropenia, however it has likewise been shown to happen outside of zinc-induced blood conditions.
In test-tube studies, excess zinc decreased the function of T cells, a kind of a white blood cell. T cells play a main function in your immune response by attaching to and damaging harmful pathogens.
Human studies also support this, however the results are less constant.
A little study in 11 healthy males discovered a reduced immune response after they ingested 150 mg of zinc twice a day for six weeks.
Nevertheless, supplementing with 110 mg of zinc 3 times a day for one month had combined impacts on older adults. Some experienced a decreased immune response, while others had an enhanced response.
If you believe you might be experiencing zinc poisoning, call your local poison control center right away.
Zinc poisoning is potentially life-threatening. For that reason, it is essential to seek medical aid right away.
You might be advised to consume milk, as the high quantities of calcium and phosphorus in it can help prevent zinc absorption in the gastrointestinal tract. Triggered charcoal has a comparable result.
Chelating agents have likewise been used in extreme poisoning cases. These assist rid the body of excess zinc by binding to it in the blood. It’s then expelled in your urine, rather than soaked up into your cells.
The Bottom Line
Although some foods include zinc well above the UL of 40 mg daily, no cases of zinc poisoning from naturally taking place zinc in food have been reported.
Nevertheless, zinc overdose can occur from dietary supplements or due to unexpected excess intake.
Zinc toxicity can have both intense and chronic effects. The intensity of your symptoms largely depends on the dose and duration of consumption.
With severe consumption of high doses of zinc, gastrointestinal symptoms are likely. In extreme cases, such as with unintentional ingestion of zinc-containing household products, gastrointestinal corrosion and bleeding can happen.
Long-term use might trigger less instant however serious side effects, such as low “good” HDL cholesterol, copper deficiency and a reduced immune system.
In general, you ought to only exceed the recognized UL under the supervision of a medical professional.