Zinc is a nutrient that supports growth during childhood and the immune system. Low zinc levels can increase a person’s risk of disease and illness.
Zinc supports a number of functions in the human body. As well as supporting the immune system, it enables the body to make proteins and DNA, contributes to wound healing, and plays a role in childhood growth and development. It also has antioxidant properties.
Zinc occurs naturally in many foods, such as beans, meat, and fish. It is also available as a dietary supplement.
This article looks at the health benefits of zinc, what happens if a person does not have enough zinc, and useful sources.
Zinc is crucial for various functions in the body, including:
1. Immune function
2. Treating diarrhea
There is evidence that it can shorten bouts of diarrhea, especially in those who do not have a nutritious diet.
3. Wound healing
Zinc plays a role in maintaining healthy skin.
People with long-term wounds or ulcers often have low zinc levels. Healthcare professionals may recommend zinc supplements for people with persistent wounds.
Research from 2018 notes that zinc plays a key role in every stage of wound healing, from skin repair to preventing infections. The authors call for more studies to identify precisely how zinc works in healing wounds. This, they say, could lead to new treatments for wounds that are hard to heal.
4. Chronic disease
Zinc has antioxidant properties. As such, it can help reduce oxidative stress. Scientists believe that there is a link between oxidative stress and chronic diseases, such as high blood pressure, diabetes, and other aspects of metabolic syndrome.
Research from 2018 suggests that zinc may help prevent metabolic syndrome. They recommend further studies to identify how zinc affects health and to see whether supplementation might be useful as a therapy.
5. Age-related macular degeneration
Zinc prevents cell damage in the retina, and it may help delay the progression of age-related macular degeneration and vision loss, according to the National Institutes of Health (NIH). However, it is unlikely to prevent the degeneration.
The authors of research from 2020 have found that a zinc deficiency may play a role in developing this degeneration. They call for further studies and suggest that zinc might contribute to new treatment approaches.
Overall, some studies suggest that supplementation may help, but the evidence is not conclusive.
6. Sexual health
Low zinc levels may lead to delayed sexual development, fertility problems, and other sexual health issues in males.
The authors of research from 2018 describe zinc as essential to male sexual health. Reasons for this could include zinc’s roles as an antioxidant and hormone balancer.
However, while a zinc deficiency can have a negative impact, too much zinc may lead to toxicity, which could be harmful to sperm.
Anyone considering zinc supplements to support their sexual health should speak with a doctor.
There is some evidence that zinc may help treat some skin diseases, as it plays a role in wound healing.
Research suggests that zinc may help treat:
However, it remains unclear whether zinc supplementation can prevent or treat this condition, and further research is necessary.
9. Neurological symptoms
A small study from 2020 concluded that there may be a link between low zinc levels and neurological symptoms.
Researchers looked at 63 people who had headaches, tingling, and peripheral neuropathy, as well as deficiencies in zinc and other micronutrients.
After treatment for these deficiencies, the participants reported improvements in their neurological symptoms. However, the researchers acknowledge the need for further research.
10. The common cold
On the whole, studies looking at the use of zinc for colds have been of poor quality. There is no reliable evidence that taking zinc prevents colds.
Also, the NIH warn that zinc can affect the sense of smell. Speak with a doctor before using nasal sprays or gels that contain zinc, as the damage may be long-term or permanent.
11. Learning and memory
Some research in rodents suggests that zinc may boost cognitive function. In a 2017 study, rats that received zinc supplements performed better in tasks that involved thinking and memory.
There does not appear to be sufficient evidence that zinc can improve memory or learning in humans, however
Some researchers have suggested that maintaining adequate zinc levels could possibly offer some protection against COVID-19.
One 2020 review notes that zinc helps boost the immune system and maintain mucous membranes. People with zinc deficiencies appear to have a higher risk of various infections, including pneumonia.
It is important to note, however, that while zinc may boost a person’s overall health and ability to resist disease, there is currently no evidence that it can prevent or treat COVID-19.
Moreover, some zinc products may lead to a permanent loss of smell.
An adequate zinc intake is especially important for children because it plays a role in their development.
The following table shows the recommended daily allowance of zinc, based on a person’s age and sex:
|0–6 months||2 mg||2 mg|
|7–12 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||11 mg||9 mg|
|19 years and over||11 mg||8 mg|
During pregnancy and breastfeeding, a higher intake of zinc is necessary, because newborns and infants up to 6 months obtain zinc through breast milk.
Good sources of zinc include:
- whole-grain cereals
- dairy products
- some fortified foods
Anyone with a plant-based diet may need additional zinc, because the zinc available in these foods is harder for the body to absorb.
Zinc is available in capsules, tablets, creams, ointments, and a liquid form.
Adults aged 19 years and over who are interested in using zinc supplements should be careful to consume no more than 40 mg per day. Too much zinc can cause health problems.
Zinc supplements are available to purchase online. However, consult a doctor before trying them.
A zinc deficiency can increase the risk of various problems, including:
- delayed growth in children
- a loss of appetite
- changes in taste
- a higher risk of infections
- fertility problems
- problems with wound healing
- eye and skin lesions
- problems with thinking
A zinc deficiency usually results from an insufficient dietary intake, but it can also result from malabsorption and chronic illnesses such as diabetes, cancer, liver disease, and sickle cell disease.
Zinc has many health benefits, but consuming too much can be harmful. Possible adverse effects include:
Over time, the NIH note, an excessive intake of 150–450 mg a day may lead to:
- low copper levels
- changes in iron function
- reduced immune function
- reduced levels of “good,” high-density lipoprotein cholesterol
- urogenital problems
Zinc may also interact with antibiotics and diuretics.
Zinc is essential for health, and it plays a key role in childhood development, the immune system, wound healing, and other functions.
It is best to obtain zinc from foods, such as beans, seafood, and fortified products. A doctor may prescribe supplements if there is a risk of a deficiency.
People who are pregnant, breastfeeding, or following a plant-based diet require extra zinc. However, as always, check with a doctor before using a supplement.