Exactly How Does Zinc Help The Immune System? Experts Explain

Zinc is an essential trace mineral, and the second most abundant mineral in your body1, next to iron. The fact that it's "essential" means that your body can't make zinc on its own. To get what you need, you have to consume it daily—for example, through food and supplement sources. "Trace" means that you only need small amounts of it every day, but that doesn't make it any less important.

One of the most well-noted functions of zinc is its role in immune health2. The mineral is involved in the creation of antibody molecules, which are one of the important ways the body defends itself against bacterial, viral, and other types of outside offenders, according to board-certified internist and mbg collective member Vincent M. Pedre, M.D.*

Research3 shows that a variety of critical immune cells in our innate and adaptive immune systems—monocytes, natural killer cells, neutrophils, B cells, and T cells—rely on access to zinc for their development and protection, and not getting enough of the nutrient can affect immune resilience. On the flip side, zinc supplementation can optimize their function in those who may need more of the mineral.*

Additionally, zinc acts as an antioxidant, which strengthens your body's natural defense mechanisms. Zinc has anti-inflammatory properties4 and can help combat oxidative stress2.*

As Ashley Jordan Ferira, Ph.D., RDN, mbg's vice president of scientific affairs, concludes, "All in all, zinc is an immune essential micromineral via multiple physiological pathways—from host resistance and resilience to our body's inflammatory response and healing—this powerhouse nutrient is showing up for us."*

Because your body can't make zinc (or any mineral for that matter), you have to get it through your diet and supplemental nutrition regimen—and as it stands, 15% of U.S. adults aren't consuming enough zinc5. 

Underscoring this nationally representative zinc intake data, Ferira explains that, "we have about 40 million Americans who need to mind their zinc gap with some real intention, and they don't even know they have a problem."

There's an even higher prevalence6 of zinc inadequacy in older adults (over the age of 71), and to make matters worse, they also don't absorb zinc as efficiently7 and therefore need to pay special attention to their immune function and overall health.

Integrative allergist and immunologist Heather Moday, M.D., notes vegetarians and vegans may also have a particularly difficult time getting adequate amounts of zinc. This is partly because seafood and meat are the primary food sources of zinc but also since plant-based sources of zinc are less bioavailable8. Ferira explains this phenomenon is thanks to the "intrinsic anti-nutrient compounds, particularly phytates, in plant foods that are known to reduce absorption of zinc and other minerals in the gut."

But Ferira, a nutrition scientist and dietitian, emphasizes that these are baseline levels. For optimal health and targeted support (like if you're focusing on immunity), your body's need for and utilization of zinc might be even higher5—closer to 15 to 30 milligrams, she says. 

The type matters, too. As Ferira explains, the collective science indicates that zinc bisglycinate is the best form of supplemental zinc for several reasons. For one, it's more bioavailable than other forms because it passes through the gut wall intact.

And it doesn't stop there. This amino acid chelate form of zinc then positively affects whole-body zinc levels, too. "This superior bioavailability of zinc bisglycinate vs. other mineral complexes (zinc gluconate, picolinate, and oxide) also translates into higher plasma levels of zinc (i.e., more zinc is absorbed and makes its way to your bloodstream). In other words, zinc bisglycinate improves your overall zinc status better than other zinc supplements,"* Ferira shares.

Zinc supplements from high-quality brands are safe and well-tolerated by most people, but if you take too much, it can lead to gastrointestinal upset11. If you and your health care provider decide that zinc supplements make sense for you, stick to the proper dosages to avoid these side effects.

For most people, zinc consumption shouldn't exceed 40 milligrams per day (i.e., the tolerable upper intake level) over a prolonged period of time. If you take more than this regularly, it can interfere with your body's absorption of other important minerals, such as copper, iron, and magnesium, compromising their status in the body.