Zinc: Benefits, Deficiency, Food Sources, and Safety
Medically Reviewed by Anthony Dugarte, MD
Last Updated on January 20, 2022
Zinc is an essential nutrient that plays many vital roles in your body. Getting the right amount of zinc will provide health benefits, but getting too much can lead to unpleasant side effects.
Zinc is an essential nutrient that plays a vital role in various processes within your body. It supports protein synthesis, DNA synthesis, immune functioning, and wound healing.
This vital nutrient also supports normal growth and development throughout pregnancy and in childhood and adolescence.
Zinc can also act as an antioxidant within your body. Antioxidants are essential compounds that can help protect cells in your body from damage caused by free radicals.
Free radicals are harmful chemicals that can contribute to the aging process and the development of several health conditions, including heart disease, asthma, diabetes, dementia, and some cancers.
Your body doesn’t make or store zinc, so daily zinc intake is required for optimal levels to help support your wellbeing.
Zinc is naturally present in some foods, added to others, can be found as a dietary supplement, or added to some over-the-counter medications.
You may be wondering, what does zinc do for the body? Surprisingly, zinc is the second most abundant trace mineral in your body and can be found working in every cell.
As mentioned previously, zinc plays many vital roles within your body and comes with a host of health benefits.
The following are the health benefits of zinc:
Zinc plays an essential role in enhancing the health of your skin by helping to produce collagen, decreasing inflammation, and promoting immune functioning.
Interestingly, the top layer of your skin contains more zinc than layers underneath.
Since zinc is responsible for supporting the growth of new, healthy skin cells, having adequate amounts can provide a host of skin health benefits.
Zinc can help treat skin lesions, decrease the severity of acne, and even reduce the signs of aging.
You’ll often find zinc oxide in wound healing products and sunscreen. This compound has been shown to promote wound healing and protect the skin from the sun’s harmful rays.
One 2014 review of studies on zinc’s role in dermatology found that zinc can be used for many skin disorders, including leg ulcers, pressure ulcers, diabetic foot ulcers, eczemas, and various skin infections. (1)
In addition, a 2020 review found that zinc is beneficial for many inflammatory skin conditions such as acne, dermatitis, and diaper rash. (2)
Zinc can benefit your skin health by playing a role in collagen production, decreasing inflammation, and enhancing cell turnover.
Zinc can help reverse the signs of aging, reduce acne, heal ulcers, and may reduce skin infections.
Zinc is vital for your immune system functioning and helps to support essential immunity cells, including neutrophils and killer cells.
Studies have shown that people who are deficient in zinc are more susceptible to infections. (3)
Zinc also appears to play a role in reducing the severity of the common cold.
A 2013 review of 18 studies found zinc lozenges (at least 75 mg a day) taken within 24 hours of the onset of symptoms reduced the duration of cold symptoms in healthy people. (4)
A 2020 review found similar benefits, with zinc supplementation decreasing cold duration by 2.25 days. (5)
Another 2013 study concluded that zinc lozenges when given within 24 hours of the onset of common cold, can be very effective in decreasing the duration and severity of a cold. (6)
Researchers believe that zinc inhibits the replication of some viruses and has antioxidant and anti-inflammatory properties, which may help to reduce the duration and severity of a cold.
Zinc can help strengthen your immune system, and a deficiency may lead to an increase in infections.
Studies indicate that lozenges containing zinc may reduce the duration and severity of the common cold.
Reduces the Risk of Certain Age-Related Diseases
Zinc may help reduce the risk of infections in older adults and reduce the risk of developing age-related macular degeneration (AMD).
The 3,640 participants were randomly assigned to daily receive orally one of the following:
- Antioxidants (500 mg of vitamin C, 400 IU of vitamin E, and 15 mg of β-carotene)
- Zinc (80 mg as zinc oxide) and copper (2 mg as copper oxide)
- Antioxidants plus zinc
In the group taking the antioxidants plus zinc supplements, the risk of developing AMD was reduced by 25% and vision loss by 19%.
In the group taking zinc and copper, the risk of developing AMD was reduced by 21% and vision loss by 11%.
One 2013 study showed that zinc supplementation (45 mg a day of zinc) in the elderly participants decreased the incidence of infections by nearly 66%. (6)
Researchers also found that stress markers and inflammation within the body were significantly reduced with zinc supplementation, suggesting that zinc may effectively prevent some chronic diseases.
Zinc appears to play a role in reducing the risk of infections in older adults and may also reduce the risk of developing age-related macular degeneration.
The Recommended Dietary Allowance (RDA) for zinc is the average daily level of intake sufficient to meet the nutrient requirements of nearly all healthy people.
The current RDAs for zinc are as follows: (8)
|0–6 months||2 mg||2 mg||-||-|
|2–12 months||3 mg||3 mg||-||-|
|1–3 years||3 mg||3 mg||-||-|
|4–8 years||5 mg||5 mg||-||-|
|9–13 years||8 mg||8 mg||-||-|
|14–18 years||9 mg||9 mg||12 mg||13 mg|
|19+ years||8 mg||8 mg||11 mg||12 mg|
Most healthy adults require 8 mg of zinc per day.
A severe zinc deficiency isn’t very common but can be seen in specific populations.
People at risk of a zinc deficiency include those with digestive disorders who don’t absorb this nutrient well.
Additionally, people with chronic liver or kidney disease and alcoholism are at risk for a zinc deficiency.
Prolonged diarrhea can lead to a zinc deficiency and severe medical conditions such as burns or sepsis, which can increase the body’s need for zinc.
Other groups at risk for zinc deficiency include:
Pregnant and Lactating Women
During pregnancy, there are increased zinc needs for the fetus. Breastfeeding can also reduce a mother’s zinc supply.
Consequently, the RDA for zinc is higher for pregnant and breastfeeding women than for other women.
Older Infants Who Are Exclusively Breastfed
Breastmilk will provide adequate amounts of zinc for a baby’s first 4–6 months of life.
However, breastmilk does not provide the recommended amounts of zinc for infants aged 7–12 months. Therefore, this age group should consume zinc-containing foods such as small pieces of hamburger meat or chicken, yogurt, and chickpeas.
There are some circumstances in which children may benefit from a zinc supplement to improve their growth rate. One 2018 meta-analysis found that zinc supplementation in infants and young children supported healthy growth and led to increased height and weight. (9)
Vegetarians and Vegans
Additionally, vegetarians typically have a higher intake of legumes and whole grains, which contain phytates (a compound found in plant seeds) that bind zinc and reduces its absorption.
For these reasons, vegetarians can sometimes require 50% more of the RDA for zinc than non-vegetarians.
Those at risk for a zinc deficiency include people with digestive disorders, those with chronic kidney or liver disease, people with alcoholism, and those with severe burns or infections.
Additionally, pregnant and lactating women, older infants that are exclusively breastfed, and people following a vegetarian or vegan diet are also at risk for zinc deficiency.
Research has found that zinc supplementation in infants and young children may lead to increases in height and weight.
Zinc Deficiency Symptoms
According to the National Institutes for Health, a zinc deficiency is characterized by delayed growth in infants and children, loss of appetite, and decreased immune functioning. (8)
In more severe deficiency cases, a person may experience hair loss, diarrhea, low testosterone production in men, eye and skin lesions, weight loss, impaired wound healing, and taste abnormalities.
Zinc deficiency is difficult to assess using a blood test; therefore, you may still be deficient even if a test indicates normal levels.
Your healthcare provider will consider your food intake, digestive issues, and various symptoms when determining your need for a zinc supplement.
Symptoms of zinc deficiency can vary from mild to severe and may include delayed growth, weight loss, impaired wound healing, and decreased immune functioning.
Animal products, like shellfish and meat, contain high amounts of zinc that your body can easily absorb. Red meat and chicken provide the majority of zinc in the American diet.
There are plant-based sources of zinc, which include beans, nuts, fortified breakfast cereals, and dairy products.
Foods highest in zinc include the following: (8)
|Food||Milligrams (mg) Per Serving|
|Oysters, 3 ounces||74|
|Crab, 3 ounces||6.5|
|Beef, 3 ounces||5.3|
|Lobster, 3 ounces||3.4|
|Pork chop loin, 3 ounces||2.9|
|Baked beans, 1/2 cup||2.9|
|Breakfast cereal, fortified, one serving||2.8|
|Chicken, dark meat, 3 ounces||2.4|
|Pumpkin seeds, 1 ounce||2.2|
|Yogurt, 8 ounces||1.7|
|Cashews, 1 ounce||1.6|
|Chickpeas, 1/2 cup||1.3|
|Cheese, Swiss, 1 ounce||1.2|
|Milk, 1 cup||1|
Animal products, including oysters, beef, and crab, contain the highest amounts of zinc that your body can easily absorb.
You may find zinc supplements in the form of tablets and capsules, but zinc is also a popular ingredient that can be added to lozenges (cough drops).
You may also come across zinc in homeopathic products intended to treat and prevent colds.
For adults, the recommended daily dosage for people that require zinc supplementation is typically 15–30 mg per day. (1)
However, it is always best to speak with your healthcare provider before taking zinc or any other supplement to ensure its safety for you.
While generally safe, zinc supplementation can cause a variety of negative symptoms when taken in excessive amounts.
Zinc supplementation, particularly when taken in doses that exceed 40 mg per day for adults (called the tolerable upper intake level), can cause adverse side effects including nausea, vomiting, loss of appetite, abdominal cramps, diarrhea, headaches, and fatigue. (8)
Zinc can interfere with the absorption of copper, leading to a deficiency of this vital mineral over time.
Moreover, zinc supplementation may decrease the effectiveness of antibiotics and a medication called penicillamine, which is used to treat rheumatoid arthritis.
The tolerable upper intake levels (ULs) for zinc are as follows: (8)
|0–6 months||4 mg||4 mg||-|
|7–12 months||5 mg||5 mg||-|
|1–3 years||7 mg||7 mg||-|
|4–8 years||12 mg||12 mg||-|
|9–13 years||23 mg||23 mg||-|
|14–18 years||34 mg||34 mg||34 mg|
|19+ years||40 mg||40 mg||40 mg|
If eating a balanced diet containing various foods, you’re likely getting the zinc you need through your food intake.
However, if you have digestive issues, follow a vegetarian or vegan diet, or are at risk for a zinc deficiency for another reason, taking a zinc supplement under the direction of your health care provider may be of benefit to you.
It’s important not to exceed the recommended dosage for zinc intake as this can lead to serious side effects and interfere with the absorption of other essential nutrients and medications.
If you and your healthcare provider decide that you may benefit from taking a zinc supplement, take it at least 1 hour before or 2 hours after your meals for increased effectiveness.
With that said, if your zinc supplement causes stomach upset, it can be taken with a meal.
Zinc plays many vital roles in your body. From supporting the health of your skin to protecting against infections as you age, having an adequate intake of this nutrient is important for your health and longevity.
At WellnessVerge, we only use primary references for our articles, including peer reviewed medical journals or well-respected academic institutions.
- Zinc Therapy in Dermatology: A Review:
- Effects of Zinc Supplementation on Inflammatory Skin Diseases: A Systematic Review of the Clinical Evidence:
- Zinc in Infection and Inflammation:
- Zinc for the common cold:
- Zinc Supplementation Reduces Common Cold Duration among Healthy Adults: A Systematic Review of Randomized Controlled Trials with Micronutrients Supplementation:
- Discovery of Human Zinc Deficiency: Its Impact on Human Health and Disease1,2,3:
- A randomized, placebo-controlled, clinical trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age-related macular degeneration and vision loss: AREDS report no. 8:
- National Institutes of Health: Zinc:
- Effect of Zinc Supplementation on Growth Outcomes in Children under 5 Years of Age: