THE LAST TIME you thought about zinc was probably in high school chemistry class when you studied the periodic table. This mineral is more than just a chemical in a textbook, though—it plays a vital role in a handful of our bodily functions. But, it often gets looked pasted since you don't need very much of it to reap its benefits.

"Even though you only need a small amount, it's involved in many important reactions in the body," says Perri Halperin, M.S., R.D., clinical nutrition coordinator at Mount Sinai Health System. The mineral plays a role in the growth of cells, healing damaged tissue, and supporting a healthy immune system. It even plays a role in the senses of taste and smell, says Erin Kenney, M.S., R.D., founder of Nutrition Rewired.

Without it, we would be in some serious trouble. Below, a full recap of everything you need to know about zinc.

What Is Zinc?

Zinc is an essential mineral that our bodies utilize to support our immune system and cellular function. Here, the word 'essential' "means the body can't make it—you need to get it from an external source like food or supplements," Halperin says.

Even though zinc plays an important role in several life-supporting bodily functions, you don't actually need that much of it. According to the Mayo Clinic, for men, about 11 milligrams will do. The need is also dependent on what's going on in your life, though. Zinc plays a crucial role in multiplying cells, so it's needed in times of rapid cell growth—think adolescence, pregnancy, and wound healing.

What Are Some Benefits of Zinc?

The two most notable benefits of zinc include supporting the immune system and helping heal damaged cells. "The greatest benefit of zinc appears to be in people who are deficient also have severe wounds (a form of damaged cells), so they have very high needs," Halperin says.

It's also been shown to assist in immune system health. In fact, zinc lozenges have been found to actually shorten the duration of a cold when taken within 24 hours of onset symptoms. Halperin says the severity of the cold has been shown to go unchanged, but the length of time the cold persists is shorter.

What Foods Contain Zinc?

If you're a person who eats shellfish, odds are you're getting enough zinc in your diet. The sea creature that contains the most? Oysters, with a whooping 291 percent of the recommended daily value of zinc in one serving. Crab, shrimp, and and sardines round out the list of fish friends that provide a decent amount of zinc. A few land neighbors—including beef, pork, and turkey—are all good sources.

Non-meat zinc sources include fortified breakfast cereals, oats, pumpkin seeds, cheese, and lentils.

How Do I Know if I'm Low on Zinc?

In the United States, about 15 percent of the population is low on zinc, according to a 2020 study published in the journal Nutrients. This can happen because of inadequate dietary intake, malabsorption issues that come with diseases like irritable bowel syndrome or inflammatory bowel disease, or other medical conditions. Those who have recently undergone bariatric surgery, like gastric bypass, may also be at risk of zinc deficiency.

Because the foods with the highest amounts of zinc include several meats, vegans and vegetarians are likely to go low on zinc. "Signs of deficiency include loss of taste, or smell, poor appetite, depressed mood, immunity, delayed wound healing, hair loss, and diarrhea," Halperin says.

Are Supplements Safe?

"It is generally recommended to obtain nutrients from a balanced diet," Kenney says. "However, certain individuals may benefit from zinc supplementation, especially those with diagnosed zinc deficiency or those at risk, such as vegetarians, vegans, and individuals with certain medical conditions."

Be careful when supplementing, though. Zinc toxicity can happen, and has been shown to come "almost exclusively" from supplements over food, Halperin says. That said, it's not recommended to eat more than 40 milligrams per day (for reference, a three ounce serving of oysters has about 30 milligrams in it). Having too much zinc can cause vomiting, poor appetite, stomach pain, headaches, and diarrhea. Zinc also interferes with the body's ability to uptake other essential minerals and nutrients like copper and iron. Similar symptoms may appear with copper and iron deficiency.

It's important to speak with a doctor, too, about what medications you're taking before you begin a zinc supplement. "Zinc may interfere with the absorption of antibiotics like tetracyclines, so it's generally recommended to separate the doses by a few hours," says Kenney. "Zinc supplements may also interact with medications used to manage rheumatoid arthritis or Wilson's disease."