Zinc is an essential nutrient that helps your immune system fight off viruses, including the common cold. It’s also been shown to improve the symptoms of atopic dermatitis, acne and psoriasis.

Zinc deficiency may cause a variety of signs and symptoms in people who are severely deficient, including loss of appetite, diarrhea and vomiting. More severe signs of zinc toxicity include intravascular hemolysis, anemia, icterus and hepatotoxicity.

Immune Function

Zinc helps your immune system fight off infections, heal wounds and make healthy cells. It is also involved in cell growth and DNA repair. Your body loses zinc during an inflammation response, so it’s important to have enough of this nutrient in your diet.

Zinc deficiency affects almost all aspects of innate immunity, including phagocytosis, intracellular killing and production of cytokines. The dysregulation of basic biological functions at the cellular level caused by zinc deficiency leads to an imbalance in Th1 versus Th2 responses and an impaired ability to combat opportunistic infections.

Taking a zinc supplement has been shown to reduce symptoms of the common cold and help fight a herpes outbreak. It may also prevent pneumonia and lower your risk of heart disease. Zinc supplements can be taken by mouth or in injections to treat esophageal and colorectal cancer, sickle cell disease, male infertility, HIV, inflammatory bowel disease (Crohn’s and ulcerative colitis), low blood sugar in diabetics, peptic ulcers, and diarrhea.

Respiratory Health

Zinc is an important mineral for your respiratory system. Several studies suggest that zinc reduces symptoms of the common cold and may have antiviral activity. Zinc also seems to prevent or shorten the duration of respiratory infections caused by influenza or rhinovirus (the virus that causes the common cold).

Researchers think that zinc improves the effectiveness of vaccines against influenza and RSV by enhancing cell-mediated immunity, modifying T cell responses, and promoting activation of regulatory T cells [45]. In addition, experimental studies show that zinc decreases lung injury from lipopolysaccharide or polymicrobial sepsis in mice by blocking inflammatory pathways, including NF-kB activation and neutrophil recruitment.

Low zinc levels are associated with male infertility, sickle cell disease, HIV infection, and type 2 diabetes. People with bariatric weight-loss surgery or gastrointestinal conditions such as Crohn’s disease have reduced absorption of zinc from food. Also, some medications such as quinolone antibiotics or tetracycline antibiotics inhibit the body’s absorption of zinc by competing with it for transport across the intestinal wall.

Wound Healing

Zinc is used for boosting immune system function, treating and preventing infections, including pneumonia, common cold, recurrent ear infections (otitis media), the flu, swine flu, and ringing in the ears; reducing the risk of age-related macular degeneration; enhancing growth and development in infants and children; and slowing the progression of diabetic foot ulcers. Zinc relieves oxidative stress, improves immune response, and enhances wound healing.

A major clinical trial found that zinc and other vitamins can help slow the progress of age-related macular degeneration, which causes central vision to deteriorate. Talk to your doctor about a treatment plan that includes zinc, vitamin C, vitamin E, beta-carotene, and copper.

Zinc supplements are generally well tolerated. However, don’t exceed the Tolerable Upper Intake Level of 40 mg per day, unless advised by your doctor. This amount can cause digestive issues and affect your sense of taste and smell. You also shouldn’t take zinc with antacids or laxatives, which can interfere with the absorption of zinc.

Skin Conditions

Zinc can help prevent and treat skin conditions. Zinc sulfate cream has been used to reduce itching due to kidney disease (dialysis) and to heal wounds after surgery for an abnormal growth at the tailbone (pilonidal surgery). Zinc ointment or tablets have been used to treat diaper rash, leishmaniasis, a severe skin disease called ichthyosis, and psoriasis, a condition that causes red, scaly patches to appear on the body. Zinc can also be used to treat the eye disease age-related macular degeneration, when taken with vitamin C and beta-carotene. (See the AREDS1 study.)

Zinc interacts with certain medications, my pham olay cua my including the antacid loperamide, which can decrease its absorption. It also may interact with cyclosporine and corticosteroids, medications that suppress the immune system. Deferoxamine (Desferal) and certain antibiotics, such as doxycycline and ciprofloxacin, may increase the amount of zinc lost in urine. Talk to your doctor before taking this supplement with these drugs.