Effects of zinc

Zinc is an essential nutrient found in many plant- and animal-based foods, as well as in supplements. It plays a key role in skin health, immune system function, and cell growth, and may protect against acne, inflammation, and other conditions.

Zinc is a nutrient that plays many vital roles in the body. Since your body does not naturally produce zinc, you must obtain it through food or supplements. This article explains everything you need to know about zinc, including its functions, health benefits, dosage recommendations, and potential side effects.

What is zinc?

Zinc is considered an essential nutrient, meaning that your body cannot produce or store it.

Therefore, you need to ensure a steady supply through your diet. Zinc is needed for numerous processes in the body, including:

• gene expression
• enzymatic reactions
• immune system function
• protein synthesis
• DNA synthesis
• wound healing
• growth and development

Zinc is naturally found in many plant- and animal-based foods.

Foods that do not naturally contain this mineral, such as breakfast cereals and snacks, are often fortified with synthetic forms of zinc.

You can also take zinc supplements or multinutrient supplements containing zinc. Because of its role in immune system function, zinc is also added to some lozenges and other natural cold remedies.

SUMMARY Zinc is an essential mineral that the body does not produce itself. It supports growth, DNA synthesis, immune function, and much more.

Role in the body

Zinc is an essential mineral that the body uses in countless ways. In fact, zinc is the second most abundant trace element in the body—after iron—and is present in every cell.

Zinc is required for the activity of more than 300 enzymes that aid metabolism, digestion, nerve function, and many other processes.

In addition, it is critical for the development and function of immune cells. This mineral is also essential for skin health, DNA synthesis, and protein production.

Moreover, the body's growth and development depend on zinc because of its role in cell growth and division.

Zinc is also necessary for the senses of taste and smell. Because one of the enzymes essential for proper taste and smell depends on this nutrient, zinc deficiency may reduce the ability to taste or smell.

SUMMARY Zinc is essential for cell growth and division, immune system function, enzyme reactions, DNA synthesis, and protein production.

Health benefits

Research shows that zinc has numerous health benefits.

Strengthens the immune system

Zinc helps keep the immune system strong.

Because it is necessary for immune cell function and cell signaling, zinc deficiency can lead to a weaker immune response. Zinc supplements stimulate certain immune cells and reduce oxidative stress.

For example, one study showed that 80–92 milligrams (mg) of zinc per day could reduce the duration of the common cold by up to 33%.

What’s more, some older research suggests that zinc supplementation significantly reduces the risk of infections and supports the immune response in older adults.

Speeds up wound healing

Zinc is often used in hospitals to treat burns, certain ulcers, and other skin injuries.

Because this mineral plays a critical role in collagen synthesis, immune function, and the inflammatory response, it is necessary for proper healing.

In fact, the skin contains a relatively large amount—about 5%—of the body’s zinc. While zinc deficiency can slow wound healing, zinc supplementation may speed healing in people with wounds.

For example, in a 12-week study involving 60 people with diabetic foot ulcers, those treated with 50 mg of zinc daily experienced a significant reduction in ulcer size compared with the placebo group.

May reduce the risk of certain age-related diseases

Zinc may significantly reduce the risk of age-related diseases such as pneumonia, infections, and age-related macular degeneration (AMD).

Zinc may alleviate oxidative stress and improve the immune response by increasing the activity of T cells and natural killer cells, which help protect the body from infections.

Some older studies suggest that older adults who took zinc supplements had improved responses to the flu vaccine, a reduced risk of pneumonia, and enhanced cognitive performance.

Moreover, a 2007 study found that 45 mg of elemental zinc per day could reduce the incidence of infections by nearly 66% in older adults.

In addition, a 2013 study involving more than 4,200 people found that daily antioxidant supplements—vitamin E, vitamin C, and beta-carotene—along with 80 mg of zinc reduced vision loss and significantly lowered the risk of advanced AMD.

May help treat pimples

Acne is a common skin condition that is estimated to affect up to 9.4% of the world's population. Acne is caused by clogged oil-producing glands, bacteria, and inflammation.

Studies suggest that both topical and oral zinc treatments can effectively treat acne by reducing inflammation, inhibiting the growth of P. acnes bacteria, and suppressing the activity of oil glands.

People with acne generally have lower zinc levels. Therefore, supplements may help reduce symptoms.

Reduces inflammation

Zinc reduces oxidative stress and lowers levels of certain inflammatory proteins in the body.

Oxidative stress leads to chronic inflammation, which plays a role in the development of many chronic diseases, such as heart disease and cognitive decline.

In a 2010 study involving 40 older adults, those who took 45 mg of zinc daily experienced greater reductions in inflammatory markers than the placebo group.

SUMMARY Zinc may effectively reduce inflammation, support immune system health, lower the risk of age-related diseases, speed wound healing, and improve acne symptoms.

Deficiency symptoms

Although severe zinc deficiency is rare, it can occur in people with rare genetic mutations, breastfed infants whose mothers do not get enough zinc, people with alcohol dependence, and those taking certain immunosuppressive medications.

Symptoms of severe zinc deficiency include impaired growth and development, delayed sexual maturation, skin rashes, chronic diarrhea, impaired wound healing, and behavioral problems.

Milder forms of zinc deficiency are more common, especially among children living in developing countries, where diets are often lacking in important nutrients.

An estimated 2 billion people worldwide have zinc deficiency due to inadequate nutrition. Because zinc deficiency damages the immune system— increasing the likelihood of infections—it is estimated to cause more than 450,000 deaths annually among children under 5.

People at risk of zinc deficiency include:

• people with gastrointestinal diseases, such as Crohn’s disease
• vegetarians and vegans
• pregnant or breastfeeding people
• older exclusively breastfed infants
• people with sickle cell anemia
• malnourished people, including those with anorexia or bulimia
• people with chronic kidney disease
• people with alcohol use disorder

Symptoms of mild zinc deficiency include diarrhea, reduced immunity, thinning hair, impaired taste or smell, dry skin, fertility problems, and impaired wound healing.

Zinc deficiency is difficult to detect with laboratory tests because the body tightly regulates zinc levels. Therefore, a person may still be deficient even when tests show normal levels.

In addition to blood test results, doctors consider other risk factors—such as poor nutrition and genetics—when deciding whether dietary supplements are needed.

SUMMARY Risk factors for zinc deficiency include inadequate dietary intake, poor absorption, alcoholism, genetic mutations, and older age.

Food sources

Many animal- and plant-based foods are naturally rich in zinc, making it easy for most people to consume adequate amounts.

Foods that are higher in zinc include:

• Shellfish: oysters, crab, mussels, lobster, and clams
• Meat: beef, pork, lamb, and bison
• Poultry: turkey and chicken
• Fish: flounder, sardines, salmon, and sole
• Legumes: chickpeas, lentils, black beans, kidney beans, etc.
• Nuts and seeds: pumpkin seeds, cashews, hemp seeds, etc.
• Dairy products: milk, yogurt, and cheese
• Eggs
• Whole grains: oats, quinoa, brown rice, etc.

Certain vegetables: mushrooms, kale, peas, asparagus, and carrot greens Animal products, such as meat and shellfish, contain large amounts of zinc in a form that the body can easily absorb.

Zinc found in plant-based sources, such as legumes and whole grains, is absorbed less efficiently because of other plant compounds that inhibit absorption.

While many foods are naturally high in zinc, certain foods—such as ready-to-eat breakfast cereals and snack bars—are fortified with zinc.

SUMMARY Zinc naturally occurs in foods such as shellfish, meat, poultry, and dairy products, and is added to other foods, such as breakfast cereals and snack bars.

Toxicity and dosage recommendations

Just as zinc deficiency can cause health complications, excessive intake can also lead to negative side effects.

The most common cause of zinc poisoning is taking too much supplemental zinc, which can cause both acute and chronic symptoms.

Symptoms of toxicity include:

• nausea and vomiting
• diarrhea
• abdominal cramps and pain
• headaches

Taking too much zinc can also cause deficiencies in other nutrients.

For example, chronically high zinc intake can interfere with the absorption of copper and iron.

A decrease in copper levels has been reported even in people who consumed moderately high doses of zinc—60 mg per day—for just 10 weeks.

Recommended doses

To avoid excessive intake, avoid high-dose zinc supplements unless recommended by a doctor.

The recommended dietary allowance (RDA) is 11 mg for adult men and 8 mg for adult women.

Pregnant and breastfeeding people should consume 11 and 12 mg per day, respectively.

Unless a health condition interferes with absorption, you should be able to meet the RDA for zinc through diet alone.

However, people with certain dietary restrictions, including vegans and vegetarians, may have difficulty meeting their needs through diet alone (1. Trusted Source).

The tolerable upper intake level for zinc is 40 mg per day. However, this does not apply to people with zinc deficiency who need to take high-dose supplements.

If you take supplements, choose absorbable forms such as zinc citrate or zinc gluconate rather than zinc oxide, which is poorly absorbed.

SUMMARY Zinc toxicity can cause diarrhea, headaches, abdominal cramps, and reduced immunity. Most people can get their daily zinc intake through diet alone.

Zinc is necessary for DNA synthesis, immune system function, metabolism, and growth.

It may reduce inflammation and the risk of certain age-related diseases.

Most people meet the RDA of 11 mg for men and 8 mg for women through their diet, but older adults, those following restrictive diets, and people with conditions that inhibit zinc absorption may need supplementation.

Because high-dose zinc supplements can lead to dangerous side effects, it is important to follow recommendations and take supplements only when necessary.

Source: www.healthline.com