Zinc: Usage, Health Benefits & Side Effects

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In order to maintain good health and function, the body requires a vast array of micronutrients every day.

While it is vital that we consume a wide range of micronutrients, zinc is a nutrient of particular importance.

In this article, we will first consider what zinc is before moving on to discuss potential benefits and considerations.

What is Zinc?

Zinc is a nutrient that is essential that we need in order to maintain good health. It cannot be synthesized or stored by the body and, therefore, must come from food sources.

The nutrient can be found in a range of both plant and animal foods. Zinc can be found most abundantly in animal meats, beans, dairy, fish, nuts, and whole grains.

For those who are deficient in zinc, supplements may be beneficial. Furthermore, many individuals seeking to optimize their health take zinc supplements.

The reason for this is that zinc plays a critical role in a number of bodily functions and processes. Immunity, healing, growth, our genes, and DNA are all influenced by zinc (1).

There are actually many different types of zinc supplements – zinc acetate, citrate, gluconate, orotate, picolinate, and sulfate, for example.

While the different types of zinc products will boost overall zinc-levels, some types have better absorption rates and uses.

How Does It Work?

Zinc aids the immune system and helps it to fight off invading bacteria and viruses that cause disease and illness. In addition, it also appears to accelerate wound healing.

The nutrient plays an important role in synthesizing all genetic material held within the cells, known as DNA. As well as DNA, zinc is a key component of protein and enzyme production.

Zinc is also vital in growth, development, and maturation, especially in the early years of life.

Failing to consume enough zinc may have adverse effects on the body. Anemia, suppressed immunity, skin conditions, stunted growth, and altered cognition have all been reported.

Is It Safe?

When no more than 40 mg of zinc is taken per day, zinc appears to be safe. However, it may cause side effects with certain individuals.

If exceeding 40 mg, the risk of experiencing side effects and developing issues is potentially greater. Side effects such as flu-like symptoms and digestive issues may occur.

There is concern regarding high zinc doses and its impact on red blood cells. A high dose of zinc has been associated with reducing the amount of copper that the body can absorb.

By reducing the amount of copper, the risk of developing anemia appears to increase (2).

Zinc Health Benefits

Health Benefits of Zinc

There are a number of possible benefits associated with increasing zinc intake. This section will review the scientific research that has been conducted on zinc supplementation.

1. Enhances Immune Function

What the Science Says

Research into zinc has indicated that the nutrient may improve immune function. Therefore, it is not uncommon to find a number of natural remedies and medications contain zinc.

The common cold is an illness for which there is no cure. However, research has shown that taking zinc supplements may help to reduce the duration of a cold by 33% (3).

Zinc may also reduce inflammation and prevent oxidative stress. Consequently, this may help to reduce the risk of developing diseases such as cancer, diabetes, and heart disease.

To add weight to this, one study investigated the impact of zinc supplementation on inflammatory markers and infection frequency.

The results indicated that by taking 45 mg of zinc gluconate for one year, participants decreased inflammation and infection frequency (4).

2. Accelerates Wound Healing

What the Science Says

Zinc plays a key role in a process known as collagen synthesis. Collagen is a substance made by the body which is needed for structure, remodeling, and wound healing.

Therefore, by increasing zinc intake and enhancing collagen synthesis, wound healing may improve – especially for those who are zinc deficient.

This helps to explain why zinc is commonly used as a treatment for skin injuries such as burns and ulcers.

A study conducted into individuals with foot ulcers found that a zinc treatment caused significant reductions in ulcer size (5).

3. Better Blood Sugar Control

What the Science Says

Preventing blood sugar levels from becoming excessively elevated is important for maintaining good health. For diabetics, controlling blood sugar levels is absolutely critical.

Scientific studies have indicated that zinc may play a role in controlling blood sugar levels.

Insulin is the hormone that regulates blood sugar levels. Studies have suggested that zinc can improve the body’s sensitivity to insulin.

As well as improving sensitivity, additional research indicates that zinc may also reduce insulin resistance (6). A combination of these two will lead to greater control over blood sugar.

Results from one particular review concluded that zinc supplements may help diabetics improve short-term and long-term blood sugar control (7).

4. Promotes Heart Health

What the Science Says

Cardiac-related diseases cause millions of deaths globally each year. By maintaining a healthy diet and exercising often, many of these conditions are preventable.

Studies have suggested that zinc may reduce the risk of developing many of these diseases. It appears to do this by reducing cholesterol and triglyceride levels within the blood.

A meta-analysis into the matter concluded that zinc supplements decreased LDL cholesterol and triglyceride levels (8).

Another common factor that influences heart disease is blood pressure.

A second study determined that high zinc intakes lead to lower levels of systolic blood pressure (9). That said, more research is required to confirm these findings.

5. Improves Skin Health

What the Science Says

As highlighted previously, zinc appears to enhance collagen synthesis and consequently accelerate wound healing.

In a similar way, zinc supplements may have a positive impact on skin health and skin conditions.

Zinc appears to be particularly effective for decreasing symptoms of acne. Results from one study demonstrated zinc supplementation was an effective treatment for inflammatory acne (10).

From a practical standpoint, zinc supplements tend to be favored over other products. This is primarily due to the fact that they are inexpensive and cause few side effects.

6. Slows Macular Degeneration

What the Science Says

Macular degeneration is an age-related eye disease that can cause blurry or no vision.

Zinc supplements are commonly prescribed to those affected by this disease to slow its progression and prevent vision loss.

Research has shown that daily zinc sulfate supplements can help to slow the development of macular degeneration (11).

However, there are studies to suggest that zinc supplements may need to be paired with other treatments to maximize results (12).

7. Enhances Digestive Health

What the Science Says

There are a number of gastrointestinal conditions that can contribute to a zinc deficiency.

Therefore, for those who suffer from conditions such as Crohn’s and ulcerative colitis, it may be necessary to supplement zinc.

Furthermore, a review of zinc supplementation has indicated that it may be beneficial for a range of gastrointestinal issues.

It is theorized that zinc can improve something known as epithelial barrier function which consequently facilitates better digestive health (13).

Side Effects

When used safely, zinc supplements can effectively boost zinc intake in a safe and effective manner. That said, they have been linked with a number of side effects including:

  • Diarrhea
  • Flu-like symptoms
  • Nausea
  • Stomach pain
  • Vomiting

Usage and Dosing Considerations

Zinc intake can be increased by consuming zinc-rich foods or through supplementation. While supplementation is a highly convenient method, it must be carried out safely.

There is a range of zinc products available with different outcomes and formulations. Speak to a nutritionist or dietician for further guidance on the most suitable product.

To ensure that you are supplementing zinc safely, always follow the dosage guidelines on the products.

Additionally, it is always recommended to speak with a doctor prior to taking any new supplement.

Risks and Precautions

Taking 40 mg of zinc per day appears to be safe for most individuals. However, exceeding 40 mg per day may increase the risk of developing side effects and other issues.

Taking large doses consistently over a number of years has been associated with an increased risk of prostate cancer (14).

Research has also suggested zinc supplementation can impact copper and iron levels and lead to anemia (15).


What are the differences between zinc supplements?

There are a number of forms of zinc supplement – acetate, citrate, gluconate, orotate, picolinate, and sulfate.

These terms refer to the amino acid that zinc has been bonded to in order to allow absorption to occur. For example, zinc orotate is zinc that has been bonded to orotic acid.

Which type of zinc is best?

Some types, such as zinc citrate and gluconate, seem to be absorbed by the body more efficiently (16).

However, some products have specific uses such as treating cold symptoms, boosting the immune system, or reducing acne.

To understand which type of zinc supplement has the greatest impact, speak to a qualified nutritionist or dietician.

How much zinc should be taken per day?

This is dependent on a number of factors including age, physical characteristics, the purpose of supplementation, and the zinc supplement used.

As highlighted, the upper recommended limit of zinc is 40 mg per day. With that being said, there are a number of considerations to be made before deciding on a suitable dose.

When should zinc supplements be taken?

For optimal results, it is recommended to take zinc supplements one hour prior or two hours after a meal. If this causes digestive issues, supplements can be taken with a meal.

That said, always adhere to the dosage instructions of the zinc supplement being used.

Who should not take zinc supplements?

Zinc can interact with other medications and actually reduce the amount of zinc absorbed by the body (17).

Therefore, those who take medication for any reason must consult a doctor before starting zinc supplements.

Does taking zinc prevent colds?

Zinc supplements are often used as a method of preventing the common cold.

Some studies have found zinc may indeed reduce the duration of colds, however, in terms of prevention, there are conflicting findings (18).

Therefore, it is currently unclear whether zinc prevents colds or not – more research is required.


When used appropriately, zinc may positively improve health in a number of ways.

It appears to significantly boost the immune system and may reduce the duration of certain illnesses, such as the common cold.

Furthermore, research suggests it may improve heart health, digestive health, and blood glucose control. In turn, this can significantly reduce the risk of developing chronic diseases.

Zinc is also commonly prescribed to effectively reduce symptoms of skin conditions, such as acne, and prevent macular degeneration.

While much research has been conducted on zinc supplementation, additional research should be conducted to confirm these findings.

Providing recommended doses are adhered to, the risk of experiencing severe side effects is low. That said, it is crucial that a doctor is consulted before taking a zinc supplement.



  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3724376/
  2. https://www.ncbi.nlm.nih.gov/books/NBK225396/
  3. https://www.ncbi.nlm.nih.gov/pubmed/28515951
  4. https://www.ncbi.nlm.nih.gov/pubmed/17344507
  5. https://www.ncbi.nlm.nih.gov/pubmed/28395131
  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4360427/
  7. https://www.ncbi.nlm.nih.gov/pubmed/22515411
  8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4523910/
  9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3796663/
  10. https://www.ncbi.nlm.nih.gov/pubmed/11586012
  11. https://www.ncbi.nlm.nih.gov/pubmed/25393287
  12. https://www.ncbi.nlm.nih.gov/pubmed/23652490
  13. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4231515/
  14. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6356690/
  15. https://www.ncbi.nlm.nih.gov/pubmed/12097660
  16. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3901420/
  17. https://ods.od.nih.gov/factsheets/Zinc-Consumer/#h8
  18. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3273967/

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