Zinc (Zn)

What is zinc?

Zinc is an essential mineral that supports immune function, growth and development, and brain health, among other things. Since our bodies cannot produce zinc in adequate amounts, we must get it through our diet.

Why we need it

Zinc is critical for our immune health, as it helps us heal wounds and fight off illness and infection. Zinc promotes immune function through a variety of mechanisms. For instance, it supports the development and function of immune cells like T cells, B cells, neutrophils, and macrophages.¹ Additionally, zinc helps protect against inflammation by downregulating the production of inflammatory cytokines.¹ Zinc also has antioxidant activity, which means it helps protect us against oxidative stress (a phenomenon that can contribute to aging and disease). Specifically, zinc supports the structure of superoxide dismutase, an antioxidant enzyme.²

Zinc is also essential for brain health. It helps our bodies form myelin, which is a protective coating that covers our brain cells.³ Zinc also helps us transmit signals throughout the brain, and it promotes the development of new brain cells.³ Similarly, zinc is crucial for general growth and development, as it helps our cells divide and replicate. This is why getting enough zinc is especially important during periods of growth, such as during childhood, puberty, and pregnancy.

Where it’s found

Zinc is found in a wide variety of foods, including both animal-based and plant-based foods. Zinc may be naturally present in food, or added in through fortification. Examples of zinc-rich foods include:

Seafood
Red meat
Poultry
Yogurt
Beans
Milk
Fortified breakfast cereals
Cheese

You can also get zinc from dietary supplements. Zinc can be taken as a standalone supplement, or as part of a multivitamin. Zinc supplements are available in many forms, including tablets, lozenges, and nasal sprays.⁴

Daily requirements

The daily Recommended Dietary Allowance (RDA) for zinc, or the amount that is likely to meet the needs of most healthy people, is 3 milligrams (mg) for children aged 1-3 years, 5 mg for children aged 4-8 years, 8 mg for adolescents aged 9-13 years, 11 mg for male adolescents aged 14-18 years, 9 mg for female adolescents aged 14-18 years, 11 mg for men aged 19 and up, and 8 mg for women aged 19 and up.⁵ For women who are pregnant or breastfeeding, the RDA increases by 3 mg per day and 4 mg per day, respectively.⁵

Zinc deficiency

Zinc deficiency can have many consequences on health. It can weaken our immune system, making us more susceptible to illness and infection. Zinc deficiency is particularly harmful during periods of growth. It can lead to cognitive impairment, memory issues, stunted growth, and other serious consequences.³

Zinc deficiency is quite common in low-income countries, due to low zinc consumption.⁶ Zinc deficiency is less prevalent in higher-income countries, but it still occurs. Groups that may be at higher risk for zinc deficiency include people with inflammatory diseases, older adults, and people who do not eat meat.⁶

Can you get too much zinc?

Zinc can be harmful when consumed in excessive amounts. Symptoms of zinc toxicity include nausea, vomiting, stomach pain, low appetite, diarrhea, and headaches. Over prolonged periods, zinc toxicity can negatively affect our immune function and cholesterol levels, and it can cause us to become deficient in other nutrients, such as copper.⁵

The Tolerable Upper Intake Level for zinc is 40 mg for adults.⁵ This value represents the maximum daily amount that is unlikely to cause toxicity.

Fun facts

Many plant-based foods contain phytic acid, a compound that can interfere with our ability to absorb zinc. Thus, while many plant-based foods have a high zinc content, we may absorb only a fraction of it.

Oysters are the richest dietary source of zinc. A single steamed oyster provides about 9.4 mg of zinc, which is over 100% of the RDA for women and over 80% of the RDA for men.⁷