Zinc is a trace mineral that’s essential for keeping a variety of body systems working properly. According to the National Institutes of Health (NIH), zinc sparks roughly 100 enzymatic functions, aids in protein and DNA synthesis, supports immunity via its antioxidant properties, helps heal wounds and propels normal growth during childhood, adolescence and pregnancy. Not surprisingly, getting too little zinc can cause stunted growth and delayed puberty in kids, slow wound healing, hair loss, frequent infections and impaired sight, smell and taste.

Because the body doesn’t retain significant zinc stores, it’s imperative to re-up on the mineral regularly through food and, if necessary, dietary supplements. Luckily, a broad range of foods contain zinc, giving us ample opportunity to work enough of it into our diets. According to the U.S. Department of Agriculture’s National Nutrient Database for Standard Reference, oysters are by far the richest source, but red meat, roast beef, crab, fortified breakfast cereals, chicken, cashews, baked beans, yogurt, pork chops and chickpeas all offer significant quantities, while vegetables contain lesser amounts. 

Unlike many other nutrients, zinc is available in a mix of many meats, dairy and grains—which is part of the reason that, even despite the not-so-healthy typical Western diet, zinc deficiency remains uncommon in the U.S. But if the diet doesn’t provide enough zinc, a daily multivitamin can easily bump intake to meet the Institute of Medicine’s recommended daily allowance of 8 to 11 mg per day for adults.

Still, certain groups have heightened risk of zinc deficiency. According to the NIH, these include pregnant and breastfeeding women, since they share zinc intake with their offspring; people with gastrointestinal diseases and digestive disorders that hinder absorption; and heavy drinkers, because alcohol disrupts the intestines’ ability to absorb zinc and increases the amount that gets flushed out with urine.    

Vegetarians need to mind their minerals too, because zinc from plant sources is less bioavailable than that from meat. Although packed with nutrients, the salad greens, legumes and whole grains that vegetarians tend to favor contain compounds called phytates that get in the way of absorption, the NIH reports. That’s why non-meat-eaters can require up to 50 percent more zinc per day than carnivores.

Now that you know how to get it, here’s a closer look at a few of zinc’s well-established benefits.

Immune support

While full-blown zinc deficiency can derail the body’s ability to fend off harmful bacteria and viruses, research shows that having even slightly low levels can hamper immune function. A review of zinc and other essential minerals published in Annals of Nutrition and Metabolism in April 2007 stressed zinc’s job of keeping the body’s antibody responses alert and active. A slightly older, large-scale research review, published in the American Journal of Clinical Nutrition in 1998, outlined the myriad biological ways in which zinc affects immunity, from its ability to shield cells from disease-causing free radicals to its role in strengthening white blood cells’ infection-zapping powers. 

Common cold relief 

Zinc supplements, lozenges and nasal sprays have shown great promise in fighting acute colds and other upper respiratory woes. A study published in the Journal of Infectious Diseases in March 2008 found that zinc lozenges significantly reduced common cold symptoms such as nasal drainage and cough and cut the duration of sickness by two to three days compared to placebo. Researchers attributed these results to zinc’s anti-inflammatory and antioxidant capabilities. 

In February 2011, Cochrane Database of Systematic Reviews published an analysis of randomized, double-blind, placebo-controlled trials assessing zinc’s impact on common colds. The results? When administered within 24 hours of the onset of symptoms, zinc reduces cold duration and severity in otherwise healthy people. What’s more, the researchers determined zinc also cuts down cold incidences, days missed from school and the amount of antibiotic prescriptions filled for children when given as a supplement for at least five months.

Wound healing

Since zinc is such a solid immune-booster, it’s not surprising that it also helps heal sores, cuts, scrapes, burns and lesions—even those caused by acne, some studies have found. According to the NIH, zinc helps keeps skin cells strong and intact and supports mucosal membranes, which help damaged skin spring back into shape. Studies of hospital patients and people with compromised mobility, including an evaluation published in the Scottish journal Clinical Nutrition in January 2005, have found that zinc supplements speed the healing time of pressure ulcers, also known as bedsores.    

Diarrhea defense

Often sparked by infection or illness, diarrhea can cause serious malnutrition—and serious malnutrition can foster further diarrhea. This vicious cycle is common among children of impoverished nations. Several studies throughout the 2000s confirmed that zinc supplements significantly decreased the severity and duration of diarrhea among ill children in such situations. While most Americans are better nourished, these findings underscore zinc’s effectiveness in maintaining regularity and overall wellness.