What is it?
Zinc is a metal. It is called an “essential trace element” because very small amounts of zinc are necessary for human health.
Zinc is used for treatment and prevention of zinc deficiency and its consequences, including stunted growth and acute diarrhea in children, and slow wound healing.
It is also used for boosting the immune system, treating the common cold and recurrent ear infections, and preventing lower respiratory infections. It is also used for malaria and other diseases caused by parasites.
Some people use zinc for an eye disease called macular degeneration, for night blindness, and for cataracts. It is also used for asthma; diabetes; high blood pressure; acquired immunodeficiency syndrome (AIDS); and skin conditions such as psoriasis, eczema, and acne.
Other uses include treating attention deficit-hyperactivity disorder (ADHD), blunted sense of taste (hypogeusia), ringing in the ears (tinnitus), severe head injuries, Crohn’s disease, Alzheimer’s disease, Down syndrome, Hansen’s disease, ulcerative colitis, peptic ulcers and promoting weight gain in people with eating disorders such as anorexia nervosa.
Some people use zinc for benign prostatic hyperplasia (BPH), male infertility, erectile dysfunction (ED), weak bones (osteoporosis), rheumatoid arthritis, and muscle cramps associated with liver disease. It is also used for sickle cell disease and inherited disorders such as acrodermatitis enteropathica, thalassemia, and Wilson’s disease.
Some athletes use zinc for improving athletic performance and strength.
Zinc is also applied to the skin for treating acne, aging skin, herpes simplex infections, and to speed wound healing.
There is a zinc preparation that can be sprayed in the nostrils for treating the common cold.
Zinc sulfate is used in products for eye irritation.
Zinc citrate is used in toothpaste and mouthwash to prevent dental plaque formation and gingivitis.
Note that many zinc products also contain another metal called cadmium. This is because zinc and cadmium are chemically similar and often occur together in nature. Exposure to high levels of cadmium over a long time can lead to kidney failure. The concentration of cadmium in zinc-containing supplements can vary as much as 37-fold. Look for zinc-gluconate products. Zinc gluconate consistently contains the lowest cadmium levels.
Natural Medicines rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.
The Effectiveness ratings for Zinc are as follows:
- Zinc deficiency. Zinc deficiency might occur in people with severe diarrhea, conditions that make it hard for the bowel to absorb food, liver cirrhosis, and alcoholism. It may also occur after major surgery and during long-term use of tube feeding in the hospital. Taking zinc by mouth or giving zinc intravenously (by IV) helps to restore zinc levels in people who are zinc deficient. However, taking zinc supplements regularly is not recommended.
Likely Effective for…
- Diarrhea. Taking zinc by mouth reduces the duration and severity of diarrhea in children who are undernourished or zinc deficient. Severe zinc deficiency in children is common in developing countries. Also giving zinc to undernourished women during pregnancy and for one month after delivery reduces the incidence of diarrhea in infants during the first year of life.
- An inherited disorder called Wilson’s disease. Taking zinc by mouth improves symptoms of an inherited disorder called Wilson’s disease. People with Wilson’s disease have too much copper in their bodies. Zinc blocks how much copper is absorbed and increases how much copper the body releases.
Possibly Effective for…
- Acne. Research suggests that people with acne have lower blood and skin levels of zinc. Taking zinc by mouth appears to help treat acne. However, it’s unclear how beneficial zinc is compared to acne medications such as tetracycline or minocycline. Applying zinc to the skin in an ointment does not seem to help treat acne unless used in combination with the antibiotic drug called erythromycin.
- An inherited disorder that affects zinc uptake (acrodermatitis enteropathica). Taking zinc by mouth seems to help improve symptoms of acrodermatitis enteropathica.
- Age-related vision loss (age-related macular degeneration). People who consume more zinc as part of their diet seem to have a lower risk of developing age-related vision loss. Research shows that taking supplements containing zinc and antioxidant vitamins may modestly slow vision loss and prevent age-related vision loss from becoming advanced in people at high risk. It’s still not clear if taking zinc along with antioxidant vitamins helps prevent age-related vision loss from becoming advanced in people at low risk. Most research shows that taking zinc alone, without antioxidant vitamins, does not help most people with age-related vision loss. However, it’s possible that people with certain genes that make them susceptible to age-related vision loss might benefit from zinc supplements.
- Anorexia. Taking zinc supplements by mouth might help increase weight gain and improve depression symptoms in teens and adults with anorexia.
- Attention deficit-hyperactivity disorder (ADHD). Taking zinc by mouth in combination with conventional treatment might slightly improve hyperactivity, impulsiveness, and socialization problems in some children with ADHD. However, zinc does not seem to improve attention span. Some research suggests that children with ADHD have lower zinc levels in their blood than children without ADHD. Other research suggests people with ADHD with lower zinc levels might not respond well enough to prescription medications for ADHD (stimulants). Studies using zinc for ADHD have taken place in the Middle East where zinc deficiency is relatively common compared to Western countries. It is not known if zinc would have the same potential benefits when used for ADHD in people from Western countries.
- Burns. Giving zinc intravenously (by IV) together with other minerals seems to improve wound healing in people with burns. However, taking zinc alone does not appear to improve wound healing in all people with burns, but it might reduce recovery time in people with severe burns.
- Tumors in the rectum and colon. Research suggests that taking a supplement containing selenium, zinc, vitamin A 2, vitamin C, and vitamin E by mouth daily for 5 years reduces the risk of recurrent large-bowel tumors by about 40%.
- Common cold. Although some conflicting results exist, most research shows that taking lozenges containing zinc gluconate or zinc acetate by mouth helps reduce the duration of a cold in adults. However, side effects such as bad taste and nausea might limit its usefulness. It is unclear if zinc helps prevent common colds. In adults, taking zinc supplements by mouth does not seem to prevent common colds. However, zinc gluconate lozenges might help prevent colds in children and adolescents. Using zinc as a nose spray does not seem to help prevent colds.
- Depression. Early research suggests that zinc levels are lower in people with depression. Ingesting more zinc is associated with less risk of depression. Some research suggests that taking zinc along with antidepressants improves depression in people with major depression. However, other research shows that it improves depression in only people who do not respond to treatment with antidepressants alone. It doesn’t seem to improve depression in people who respond to antidepressant treatment.
- Foot ulcers due to diabetes. Research suggests that applying zinc hyaluronate gel can help foot ulcers heal faster than conventional treatment in people with diabetes.
- Diaper rash. Giving zinc gluconate by mouth to infants seems to speed up the healing of diaper rash. Applying zinc oxide paste also seems to improve the healing of diaper rash. However, it doesn’t seem to work as well as applying 2% eosin solution.
- Gingivitis. Using toothpastes containing zinc, with or without an antibacterial agent, appears to prevent plaque and gingivitis. Some evidence also shows that zinc-containing toothpaste can reduce existing plaque. However, other conventional treatments may be more effective. Also, most studies that showed benefit used zinc citrate in combination with triclosan, which is not available in the US.
- Bad breath. Research suggests that chewing gum, sucking on a candy, or using a mouth rinse containing zinc reduces bad breath.
- Herpes simplex virus. Applying zinc sulfate or zinc oxide to the skin, alone or with other ingredients, seems to reduce the duration and severity of oral and genital herpes. However, zinc might not be beneficial for recurrent herpes infections.
- Taste disorder (hypogeusia). Some early research suggests that taking zinc by mouth does not improve taste disorders in children with zinc deficiency. But most evidence suggests that taking zinc by mouth is effective for people with a reduced ability to taste foods due to zinc deficiency or some other conditions.
- Skin lesions (Leishmania lesions). Research suggests that taking zinc sulfate by mouth or injecting as a solution into lesions helps heal lesions in people with Leishmaniasis. However, injecting zinc solutions into lesions does not seem to be more effective than conventional treatments.
- Leprosy. Taking zinc by mouth in combination with anti-leprosy drugs seems to help treat leprosy.
- Muscle cramps. Taking zinc by mouth seems to help treat muscle cramps in people with cirrhosis and zinc deficiency.
- Weak bones (osteoporosis). Low zinc intake seems to be linked to lower bone mass. Taking a zinc supplement in combination with copper, manganese, and calcium might decrease bone loss in women who have passed menopause.
- Peptic ulcers. Taking zinc acexamate by mouth seems to help treat and prevent peptic ulcers. However, this form of zinc is not available in the US.
- Pneumonia. Most research suggests that taking zinc might help PREVENT pneumonia in undernourished children. However, research assessing the effects of zinc for TREATING pneumonia once it develops shows conflicting.
- Sore throat after surgery. Using a zinc lozenge before surgery that involves having a tube placed into the windpipe seems to reduce the chance of having a sore throat after surgery.
- Complications during pregnancy. Taking zinc by mouth during pregnancy appears to reduce the risk for early delivery. However, zinc supplementation does not seem to reduce the risk for stillbirths, miscarriage, or infant deaths. Taking zinc with vitamin A might help restore night vision in pregnant women affected by night blindness. However, taking zinc alone does not appear to have this effect. Also, taking zinc might help to lower blood sugar in women who develop diabetes during pregnancy. But it doesn’t seem to reduce the need for a caesarean section during labor in these women.
- Bed sores. Applying zinc paste appears to help improve the healing of bed sores in elderly people. Also, increasing zinc intake in the diet seems to improve bed sore healing in hospitalized patients with bed sore.
- Food poisoning (shigellosis). Research shows that taking a multivitamin syrup containing zinc along with conventional treatment can improve recovery time and reduce diarrhea in undernourished children with food poisoning.
- Sickle cell disease. Taking zinc by mouth seems to help reduce symptoms of sickle cell disease in people with zinc deficiency. Taking zinc supplements also appears to decrease the risk for complications and infections related to sickle cell disease.
- Leg ulcers. Taking zinc sulfate by mouth appears to help some types of leg ulcers heal faster. The effects seem to be greater in people with low levels of zinc before treatment. Applying zinc paste to leg ulcers also appears to improve healing.
- Vitamin A deficiency. Taking zinc by mouth together with vitamin A seems to improve vitamin A levels in undernourished children better than vitamin A or zinc alone.
- Warts. Early research suggests that applying a zinc sulfate solution improves plane warts but not common warts. Applying zinc oxide ointment appears to be as effective as conventional treatments for curing warts. Taking zinc sulfate by mouth also appears to be effective.
Possibly Ineffective for…
- AIDS diarrhea-wasting syndrome. Taking zinc by mouth together with vitamins does not seem to improve AIDS diarrhea-wasting syndrome.
- Hair loss. Although there is early evidence that suggests taking zinc together with biotin might be helpful for hair loss, most studies suggest that zinc is not effective for this condition.
- Scaly, itchy skin (eczema). Taking zinc by mouth does not appear to improve skin redness or itching in children with eczema.
- Cataracts. Taking zinc by mouth together with antioxidant vitamins does not seem to help treat or prevent cataracts.
- Cystic fibrosis. Zinc sulfate does not appear to improve lung function in children or adolescents with cystic fibrosis, although it may reduce the need for antibiotics.
- HIV/AIDS. Taking zinc by mouth along with antiretroviral therapy does not improve immune function or reduce the risk of death in adults or children with HIV.
- Pregnancy complications in women with HIV/AIDS. Taking zinc by mouth during pregnancy does not appear to reduce the risk of transmitting HIV to the infant. Also, zinc does not appear to prevent infant death or maternal wasting in pregnant women with HIV.
- Infant development. Giving zinc to infants or children at risk for having low levels of zinc does not seem to improve mental or motor development. But giving zinc to women during pregnancy might increase the growth of the child during the first year of life.
- Inflammatory bowel disease (IBD). Taking zinc by mouth does not seem to help treat IBD.
- Flu. Taking zinc supplements by mouth is unlikely to improve immune function against the flu virus in people who are not at risk for zinc deficiency.
- Ear infection. Taking zinc does not appear to prevent ear infections in children.
- High blood pressure in pregnancy. Taking zinc does not seem to reduce the risk of high blood pressure in pregnancy.
- Iron-deficiency during pregnancy. Taking zinc by mouth does not seem to help improve iron levels in women taking iron and folic acid supplements.
- Prostate cancer. Taking zinc does not seem to be linked to the risk of getting prostate cancer.
- Red and irritated skin (psoriasis). Taking zinc by mouth does not seem to help treat psoriasis.
- Joint inflammation associated with a specific skin condition (psoriatic arthritis). Taking zinc by mouth, alone or together with painkillers, has no effect on the progression of psoriatic arthritis.
- Joint inflammation (rheumatoid arthritis). Taking zinc by mouth does not seem to help treat rheumatoid arthritis.
- Rosacea. Research suggests that taking zinc by mouth daily for 90 days does not improve quality of life or symptoms associated with rosacea.
- Sexual dysfunction. Research suggests that zinc supplementation does not improve sexual function in men with sexual dysfunction related to kidney disease.
- Ringing in the ears (tinnitus). Taking zinc by mouth does not seem to help treating ringing in the ears.
- Upper respiratory tract infections. Taking zinc by mouth does not decrease the risk for upper respiratory tract infections.
Likely Ineffective for…
- Malaria. Taking zinc by mouth does not help prevent or treat malaria in undernourished children in developing countries. But some research suggests it might reduce the risk for high fevers in children with malaria.
Insufficient Evidence to Rate Effectiveness for…
- AIDS-related infections due to weakened immunity. There is some early evidence that taking zinc supplements by mouth in combination with the drug zidovudine might reduce infections that occur because of a weakened immune system. However, it might negatively affect survival in people with AIDS.
- Alcohol-related liver disease. Taking zinc sulfate by mouth might improve liver function in people with alcohol-related liver disease.
- Alzheimer’s disease. Some early research shows that zinc supplements might slow the worsening of symptoms in people with Alzheimer’s disease.
- Anemia. Research suggests that giving a porridge containing zinc and other vitamins and minerals to infants reduces the risk of anemia.
- Arsenic poisoning. Early research suggests that taking zinc together with spirulina can reduce symptoms and arsenic levels in the urine and hair of people with long-term arsenic poisoning.
- Asthma. Zinc intake does not appear to be linked to the risk for developing asthma in children.
- A blood disorder called beta-thalassemia. Early research suggests that taking zinc sulfate while undergoing blood transfusions increases growth in children with beta-thalassemia compared to blood transfusions alone.
- Brain tumor. Early research suggests that zinc intake is not linked with a reduced risk of developing brain cancer.
- An airway infection that causes swelling in the lung (bronchiolitis). Taking zinc while in the hospital might speed up recovery from this type of airway infection.
- Canker sores. Some early research suggests that taking zinc sulfate improves canker sores and prevents them from reappearing. However, other research shows no benefit.
- Chemotherapy-related complications. Research suggests that taking zinc by mouth does not affect chemotherapy-related side effects such as nausea and vomiting in children undergoing chemotherapy for leukemia. However, it seems to reduce the number of episodes of infection.
- Chemotherapy-related fatigue. Early research shows that taking zinc does not reduce tiredness or improve life quality in people with colorectal cancer receiving chemotherapy.
- A lung disease called chronic obstructive pulmonary disorder (COPD). Early research suggests that taking zinc daily after recovery from COPD-related infections reduces the risk of additional infections in older people.
- Colon and rectal cancer. Increased intake of zinc has been linked to a 17% to 20% reduced risk of colorectal cancer.
- Clogged arteries (coronary artery disease). Early research suggests that taking zinc reduces cholesterol but not triglycerides in people with clogged arteries.
- Memory loss (dementia). Research suggests that taking zinc sulfate improves behavior and social abilities in people with memory loss.
- Dental plaque. Early evidence suggests that brushing teeth with toothpaste containing zinc reduces plaque buildup.
- Diabetes. Research suggests that taking zinc alone or with other nutrients reduces blood sugar in healthy people and in those with diabetes, metabolic syndrome, or obesity.
- Nerve damage caused by diabetes (diabetic neuropathy). Research suggests that taking zinc sulfate improves nerve function and reduces blood sugar in people with nerve damage caused by diabetes.
- Down syndrome. Early research suggests that taking zinc can improve immune function and reduce infections in people with Down syndrome who are zinc deficient and have weakened immune systems. However, other research shows conflicting results.
- Epilepsy. Taking zinc might reduce how often seizures occur in children not responding well to other treatments.
- Esophageal cancer. Early research has linked low intake of zinc with an increased risk of esophageal cancer. However, other early research shows that zinc intake is not linked with the risk of esophageal cancer. It’s possible that the source of zinc (plant vs. meat) affects how beneficial it is.
- Seizures due to fever. Febrile seizures are seizures that occur during a fever. Taking zinc might prevent these seizures in children who already experienced one.
- Loss of control of bowel movements. Research suggests that applying an ointment containing zinc and aluminum to the anus three times daily for 4 weeks improves symptoms and quality of life in women with a loss of control of bowel movements.
- Stomach cancer. Early research shows that increased zinc intake is not linked to a lower risk of stomach cancer.
- Head and neck cancer. Early research suggests that zinc supplementation does not improve survival rates or reduce the spread of cancer after 3 years in people with head and neck cancer.
- Loss in brain function due to liver problems (Hepatic encephalopathy). Early research suggests that taking zinc may slightly improve mental function in people with hepatic encephalopathy. However, zinc does not appear to improve disease severity or recurrence.
- HIV-related diarrhea. Taking zinc long-term might help prevent diarrhea in adults with HIV who have low blood levels of zinc. However, zinc doesn’t seem to help treat diarrhea in adults with HIV-related diarrhea. In children with HIV, some research shows that taking zinc reduces the occurrence of diarrhea compared to placebo (sugar pills). But other research shows that it doesn’t help prevent diarrhea compared to vitamin A.
- Fertility problems in men (impotence). Some early research suggests that zinc supplementation increases sperm count, testosterone levels, and pregnancy rates in infertile men with low testosterone levels. Other research suggests that taking zinc can improve sperm shape in men with moderate enlargement of a vein in the scrotum (grade III varicocele). However, in men with fertility problems due to diseases or medical treatment, taking zinc has produced mixed results.
- Stomach infections and parasite infestations. Taking zinc alone or along with vitamin A might help treat some, but not all, parasite infections in children in developing countries. Also, some research suggests that taking zinc with vitamin A reduces the risk for some infections. However, other research suggests that zinc does not reduce the risk for infection.
- Leukemia. Research suggests that taking zinc by mouth helps improve weight gain and reduces infection rate in children and adolescents with leukemia. However, zinc does not appear to improve nutrient levels in the body so that the body can function properly.
- Newborns with low birth weight. Taking zinc during pregnancy does not seem to reduce the risk of having a newborn with low birth weight . Giving zinc to underweight infants in developing countries seems to decrease the risk of death, prevent certain complications, and improve mental ability. Giving zinc supplementation to low birth weight infants industrialized countries also seems to help prevent some complications and death. But zinc doesn’t appear to improve growth in low birth weight infants from industrialized countries.
- Brown patches on the face (melasma). Research suggests that applying a solution containing zinc to the skin daily for 2 months is less effective than standard skin bleaching treatment for people with brown patches on the face.
- Nose and throat cancer. Early research suggests that taking zinc improves survival rates after 5 years in people with a rare type of advanced nose and throat cancer.
- Jaundice in newborns. Early research suggests that taking zinc twice daily for 7 days does not improve jaundice in newborns.
- Head trauma. Administering zinc immediately after a head trauma seems to improve the rate of recovery.
- A type of cancer called non-Hodgkin’s lymphoma. Early research suggests that zinc supplementation is linked to a decreased risk of developing non-Hodgkin’s lymphoma
- Obsessive-compulsive disorder (OCD). Early research suggests that taking zinc twice daily along with the drug fluoxetine for 8 weeks reduces OCD symptoms slightly more than taking fluoxetine alone.
- Swelling and ulcers in the mouth caused by chemotherapy, radiation therapy, or hematopoietic stem cell transplantation (HSCT). Research shows that taking zinc sulfate by mouth while undergoing radiation therapy helps prevent ulcers and swelling in the mouth caused by radiation treatments. Some research shows that taking zinc sulfate by mouth reduces the severity of mouth ulcers in adults undergoing chemotherapy. However, taking zinc does appear to improve mouth ulcers caused by chemotherapy in children and adolescents. Zinc does not appear to reduce mouth ulcers in patients undergoing hematopoietic stem cell transplantation (HSCT).
- An ovary disorder known as polycystic ovary syndrome (PCOS). Some research shows that taking zinc helps prevent hair loss on the head and hair growth on the face in women with PCOS who are also taking a medication called metformin. Taking zinc does not seem to improve acne or levels of hormones in the body.
- Prostate swelling (prostatis). Taking zinc along with the drug prazosin does not seem to improve the ability to urinate or quality of life compared to taking prazosin alone in men with prostate swelling. But zinc might help to relive pain in some people with this condition.
- High bilirubin levels in the blood caused by HIV/AIDs medications. A class of antiviral medications called HIV protease inhibitors can increase levels of bilirubin in the blood. Early research suggests that taking zinc daily for 14 days decreases total bilirubin levels in the blood by 17% to 20% in people being treated with the HIV protease inhibitors atazanavir/ritonavir.
- Itching. Early research suggests that taking zinc twice daily for 2 months reduces itching in people with kidney disease who are experiencing itching due to dialysis treatment.
- Blood infection (sepsis): Taking zinc along with antibiotics might protect the brain of newborns with sepsis. It isn’t known if taking zinc can help these babies live longer.
- Recovery from surgery: Early research suggests that taking zinc reduces the healing time after surgery used to treat an abnormal skin growth located at the tailbone (pilonidal surgery).
- Bladder infection: Early research shows that taking zinc helps to improve some symptoms of a bladder infection faster in children who are also taking antibiotics. Taking zinc might reduce how often they need to go to the bathroom. It doesn’t seem to help with fever or to kill the bacteria in the bladder.
- Wound healing. Early research suggests that applying a zinc solution twice daily improves wound healing compared to applying a saline solution. However, applying zinc-containing insulin (Humulin by Eli Lilly and Company) seems to work better than solution containing zinc alone.
- Wrinkled skin. A skin cream containing 10% vitamin C as L-ascorbic acid and acetyl tyrosine, zinc sulfate, sodium hyaluronate, and bioflavonoids (Cellex-C High Potency Serum) applied for 3 months to facial skin aged by sun exposure seems to improve fine and coarse wrinkling, yellowing, roughness, and skin tone.
- Crohn’s disease.
- Ulcerative colitis.
- Other conditions.
More evidence is needed to rate zinc for these uses.
Zinc is needed for the proper growth and maintenance of the human body. It is found in several systems and biological reactions, and it is needed for immune function, wound healing, blood clotting, thyroid function, and much more. Meats, seafood, dairy products, nuts, legumes, and whole grains offer relatively high levels of zinc.
Zinc deficiency is not uncommon worldwide, but is rare in the US. Symptoms include slowed growth, low insulin levels, loss of appetite, irritability, generalized hair loss, rough and dry skin, slow wound healing, poor sense of taste and smell, diarrhea, and nausea. Moderate zinc deficiency is associated with disorders of the intestine which interfere with food absorption (malabsorption syndromes), alcoholism, chronic kidney failure, and chronic debilitating diseases.
Zinc plays a key role in maintaining vision, and it is present in high concentrations in the eye. Zinc deficiency can alter vision, and severe deficiency can cause changes in the retina (the back of the eye where an image is focused).
Zinc might also have effects against viruses. It appears to lessen symptoms of the rhinovirus (common cold), but researchers can’t yet explain exactly how this works. In addition, there is some evidence that zinc has some antiviral activity against the herpes virus.
Low zinc levels can be associated with male infertility, sickle cell disease, HIV, major depression, and type 2 diabetes, and can be fought by taking a zinc supplement.
Zinc is LIKELY SAFE for most adults when applied to the skin, or when taken by mouth in amounts not larger than 40 mg daily. Routine zinc supplementation is not recommended without the advice of a healthcare professional. In some people, zinc might cause nausea, vomiting, diarrhea, metallic taste, kidney and stomach damage, and other side effects. Using zinc on broken skin may cause burning, stinging, itching, and tingling.
Zinc is POSSIBLY SAFE when taking by mouth in doses greater than 40 mg daily. There is some concern that taking doses higher than 40 mg daily might decrease how much copper the body absorbs. Decreased copper absorption may cause anemia.
Zinc is POSSIBLY UNSAFE when inhaled through the nose, as it might cause permanent loss of smell. In June 2009, the US Food and Drug Administration (FDA) advised consumers not to use certain zinc-containing nose sprays (Zicam) after receiving over 100 reports of loss of smell. The maker of these zinc-containing nose sprays has also received several hundred reports of loss of smell from people who had used the products. Avoid using nose sprays containing zinc.
Taking high amounts of zinc is LIKELY UNSAFE. High doses above the recommended amounts might cause fever, coughing, stomach pain, fatigue, and many other problems.
Taking more than 100 mg of supplemental zinc daily or taking supplemental zinc for 10 or more years doubles the risk of developing prostate cancer. There is also concern that taking large amounts of a multivitamin plus a separate zinc supplement increases the chance of dying from prostate cancer.
Taking 450 mg or more of zinc daily can cause problems with blood iron. Single doses of 10-30 grams of zinc can be fatal.
Special Precautions & Warnings:
Infants and children: Zinc is LIKELY SAFE when taken by mouth appropriately in the recommended amounts. Zinc is POSSIBLY UNSAFE when used in high doses.
Pregnancy and breast-feeding: Zinc is LIKELY SAFE for most pregnant and breast-feeding women when used in the recommended daily amounts (RDA). However, zinc is POSSIBLY UNSAFE when used in high doses by breast-feeding women and LIKELY UNSAFE when used in high doses by pregnant women. Pregnant women over 18 should not take more than 40 mg of zinc per day; pregnant women age 14 to 18 should not take more than 34 mg per day. Breast-feeding women over 18 should not take more than 40 mg of zinc per day; breast-feeding women age 14 to 18 should not take more than 34 mg per day.
Alcoholism: Long-term, excessive alcohol drinking is linked to poor zinc absorption in the body.
Diabetes: Large doses of zinc can lower blood sugar in people with diabetes. People with diabetes should use zinc products cautiously.
Hemodialysis: People receiving hemodialysis treatments seem to be at risk for zinc deficiency and might require zinc supplements.
HIV (human immunodeficiency virus)/AIDS: Use zinc cautiously if you have HIV/AIDS. Zinc use has been linked to shorter survival time in people with HIV/AIDs.
Syndromes in which it is difficult for the body to absorb nutrients: People with malabsorption syndromes may be zinc deficient.
Rheumatoid arthritis (RA): People with RA aborb less zinc.
Interaction Rating = Minor Be watchful with this combination.
Talk with your health provider.
Amiloride (Midamor) is used as a “water pill” to help remove excess water from the body. Another effect of amiloride (Midamor) is that it can increase the amount of zinc in the body. Taking zinc supplements with amiloride (Midamor) might cause you to have too much zinc in your body.
Antibiotics (Quinolone antibiotics)
Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.
Zinc might decrease how much antibiotic the body absorbs from the gut. Taking zinc along with some antibiotics might decrease the effectiveness of some antibiotics. To avoid this interaction, take antibiotics at least 2 hours before or 4-6 hours after zinc supplements.
Some of these antibiotics that might interact with zinc include ciprofloxacin (Cipro), gemifloxacin (Factive), levofloxacin (Levaquin), moxifloxacin (Avelox), and others.
Antibiotics (Tetracycline antibiotics)
Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.
Zinc can attach to tetracyclines in the stomach. This decreases the amount of tetracyclines that can be absorbed. Taking zinc with tetracyclines might decrease the effectiveness of tetracyclines. To avoid this interaction, take tetracyclines 2 hours before or 4-6 hours after taking zinc supplements.
Some tetracyclines include demeclocycline (Declomycin), minocycline (Minocin), and tetracycline (Achromycin, Sumycin).
Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.
Cisplatin (Platinol-AQ) is used to treat cancer. Taking zinc along with EDTA and cisplatin (Platinol-AQ) might inactivate cisplatin (Platinol-AQ) therapy. It is not known for sure, though, if the amount of interference caused by zinc is significant.
Medications for diabetes (Antidiabetes drugs)
Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.
Zinc might decrease blood sugar in people with type 2 diabetes. Diabetes medications are also used to lower blood sugar. Taking zinc along with diabetes medications might cause your blood sugar to go too low. Monitor your blood sugar closely. The dose of your diabetes medication might need to be changed.
Some medications used for diabetes include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos), rosiglitazone (Avandia), chlorpropamide (Diabinese), glipizide (Glucotrol), tolbutamide (Orinase), and others.
Interaction Rating = Major Do not take this combination.
Penicillamine is used for Wilson’s disease and rheumatoid arthritis. Zinc might decrease how much penicillamine your body absorbs and decrease the effectiveness of penicillamine. Take zinc and penicillamine at least 2 hours apart.
High doses of zinc can lower beta-carotene blood levels.
Metals such as zinc might reduce the effects of bromelain. However, there are no reports of this interaction.
Calcium supplements might decrease dietary zinc absorption. This usually doesn’t seem to be much of a problem. However, this interaction can be avoided by taking calcium supplements at bedtime instead of with meals.
There is early evidence that chromium and zinc could each reduce the absorption of the other. This is probably not a problem when usual supplemental doses of zinc and chromium are taken.
Large amounts of zinc can reduce copper absorption. Taking zinc in high doses can cause significant copper deficiency and anemia, a condition in which the blood cannot carry enough oxygen. Some signs of copper deficiency have also occurred in people taking 150 mg/day or more of zinc for 2 years.
EDTA is a chemical compound that is given to people to remove excess metals in their systems, especially lead. EDTA works by binding with (chelating) the metal. Repeated high doses of EDTA, as used in chelation treatment, can reduce blood zinc levels by up to 40%. Symptoms of zinc depletion have been reported, even when supplemental zinc (15mg/day) was given. People receiving chelation therapy should be monitored for zinc depletion.
Studies on the effects of folic acid supplements on dietary zinc absorption are conflicting. Normal supplemental doses of folic acid are not likely to affect zinc balance in people with adequate dietary zinc intake.
Herbs and supplements that might lower blood sugar
Large amounts of zinc might lower blood sugar. Using it along with other herbs and supplements that have the same effect might cause blood sugar to drop too low in some people. Some of these alpha-lipoic acid, bitter melon, chromium, devil’s claw, fenugreek, garlic, guar gum, horse chestnut, Panax ginseng, psyllium, Siberian ginseng, and others.
IP-6 (Phytic acid)
Phytic acid found naturally in foods can bind zinc and reduce its absorption. However, zinc deficiency due to high dietary phytic acid levels has not been reported in Western populations. Avoid IP-6 supplements, which contain phytic acid, if you have other risk factors for zinc deficiency.
Under some circumstances, iron and zinc can interfere with each other’s absorption. To avoid this effect, take these supplements with food.
High doses of zinc supplements (142 mg/day), or high dietary zinc intake (53mg/day) seem to decrease magnesium balance. The importance of this isn’t known.
Research suggests zinc supplements can more than double the amount of manganese absorbed from supplements.
Riboflavin (Vitamin B2)
Research suggests riboflavin can improve zinc absorption. The importance of this isn’t known.
Research suggests that zinc supplements can increase blood levels of vitamin A. Theoretically, zinc might increase the effects and side effects of vitamin A.
Research suggests vitamin D is involved in zinc absorption, but it’s not clear whether vitamin D improves zinc absorption.
Taking zinc sulfate with black coffee instead of water reduces zinc absorption by half. Researchers aren’t sure why this happens or how important the interaction may be.
Dairy products, calcium-fortified foods
Calcium can decrease zinc absorption. The risk of losing too much zinc isn’t significant unless lots of dairy products are consumed along with calcium supplements. However, the body adapts over the long term, becoming more efficient at absorbing zinc and reducing zinc losses.
Eating fiber can reduce zinc absorption. However, over time the body adapts to increased dietary fiber by increasing zinc absorption.
Phytate (Phytic acid, myoinositol hexaphosphate, IP6)
Phytate is a molecule found in grains (e.g., maize, corn, sorghum), legumes, seeds (e.g., sunflower, pumpkin), and soy. Phytate can reduce zinc absorption. Some foods with higher phytate contents also have a higher zinc content (for example, whole wheat vs. white bread), canceling out the effect in zinc absorption. Some people in Middle Eastern countries have zinc deficiencies because they eat unleavened bread and maize, which contain phytate. People in Western populations most at risk are those with diets high in unrefined grains, legumes, soy protein, and calcium, and low in animal protein. However, the body adapts over the long term, becoming more efficient at absorbing zinc and reducing zinc losses.
Zinc binds to proteins, becoming available for absorption as the protein is digested. The type of protein influences how much zinc is absorbed. Animal proteins generally increase zinc absorption, although a protein in cow’s milk slows absorption down. Soy proteins also reduce zinc absorption, possibly due to their phytate content. These effects can influence zinc balance in infants; babies get the most zinc from mother’s milk, less from cow’s milk, and even less from soy-based milk. It isn’t known whether high-protein diets influence zinc balance in adults.
Vegetarian diets are often high in grains and legumes, so they contain more phytate. Zinc absorption is likely to be lower, so this type of diet is considered a risk factor for zinc depletion. However, the body adapts over the long term, becoming more efficient at absorbing zinc and reducing zinc losses.
The following doses have been studied in scientific research:
- For treating the common cold: one zinc gluconate or acetate lozenge, providing 9-24 mg elemental zinc, dissolved in the mouth every two hours while awake when cold symptoms are present.
- For diarrhea in malnourished or zinc-deficient children: 10-40 mg elemental zinc daily.
- For preventing and treating pneumonia in undernourished children in developing countries: 10-70 mg/day.
- For hypogeusia (sense of taste is abnormal): 25-100 mg zinc.
- For the eating disorder anorexia nervosa: 100 mg of zinc gluconate daily.
- For treating stomach ulcers: zinc sulfate 200 mg three times daily.
- For muscle cramps in zinc deficient people with liver disease: zinc sulfate 220 mg twice daily.
- For osteoporosis: 15 mg zinc combined with 5 mg manganese, 1000 mg calcium, and 2.5 mg copper has been used.
- For sickle cell disease: zinc sulfate 220 mg three times daily.
- To increase growth and weight gain in children with sickle cell disease who have not reached puberty: 10 mg elemental zinc per day.
- For treating attention deficit-hyperactivity disorder (ADHD) in children: doses of zinc sulfate 55 mg (15 mg elemental zinc) to 150 mg (40 mg elemental zinc) daily.
- For treating acne: 30-135 mg elemental zinc daily.
- For treating age-related macular degeneration (AMD): elemental zinc 80 mg plus vitamin C 500 mg, vitamin E 400 IU, and beta-carotene 15 mg daily.
The Institute of Medicine has established Adequate Intake (AI) levels of zinc for infants birth to 6 months is 2 mg/day. For older infants, children, and adults, Recommended Dietary Allowance (RDA) quantities of zinc have been established: infants and children 7 months to 3 years, 3 mg/day; 4 to 8 years, 5 mg/day; 9 to 13 years, 8 mg/day; girls 14 to 18 years, 9 mg/day; boys and men age 14 and older, 11 mg/day; women 19 and older, 8 mg/day; pregnant women 14 to 18, 13 mg/day; pregnant women 19 and older, 11 mg/day; lactating women 14 to 18, 14 mg/day; lactating women 19 and older, 12 mg/day.
The typical North American male consumes about 13 mg/day of dietary zinc; women consume approximately 9 mg/day.
The Tolerable Upper Intake Levels (UL) of zinc for people who are not receiving zinc under medical supervision: Infants birth to 6 months, 4 mg/day; 7 to 12 months, 5 mg/day; children 1 to 3 years, 7 mg/day; 4 to 8 years, 12 mg/day; 9 to 13 years, 23 mg/day; 14 to 18 years (including pregnancy and lactation), 34 mg/day; adults 19 years and older (including pregnancy and lactation), 40 mg/day.
Different salt forms provide different amounts of elemental zinc. Zinc sulfate contains 23% elemental zinc; 220 mg zinc sulfate contains 50 mg zinc. Zinc gluconate contains 14.3% elemental zinc; 10 mg zinc gluconate contains 1.43 mg zinc.
APPLIED TO THE SKIN:
- For acne vulgaris: zinc acetate 1.2% with erythromycin 4% as a lotion applied twice daily.
- For herpes simplex infections: zinc sulfate 0.25% applied 8 to 10 times daily or zinc oxide 0.3% with glycine applied every 2 hours while awake.
Acétate de Zinc, Acexamate de Zinc, Aspartate de Zinc, Atomic Number 30, Chlorure de Zinc, Citrate de Zinc, Gluconate de Zinc, Méthionine de Zinc, Monométhionine de Zinc, Numéro Atomique 30, Orotate de Zinc, Oxyde de Zinc, Picolinate de Zinc, Pyrithione de Zinc, Sulfate de Zinc, Zinc Acetate, Zinc Acexamate, Zinc Aspartate, Zinc Chloride, Zinc Citrate, Zinc Difumarate Hydrate, Zinc Gluconate, Zinc Methionine, Zinc Monomethionine, Zinc Murakab, Zinc Orotate, Zinc Oxide, Zinc Picolinate, Zinc Pyrithione, Zinc Sulfate, Zinc Sulphate, Zincum Aceticum, Zincum Gluconicum, Zincum Metallicum, Zincum Valerianicum, Zn.
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