Zinc: benefits, sources, intake
Overview: what is zinc?
Zinc is an essential mineral that is intrinsically present in various foods, fortified in others, and also accessible as a dietary supplement. Additionally, zinc constituents can be identified in certain cold lozenges and over-the-counter medications used for treating colds, as well as in select denture adhesive creams.
Zinc performs a multitude of roles in cellular metabolism, being indispensable for the catalytic activity of an extensive array of enzymes. It facilitates the enhancement of immune functions, as well as the synthesis of proteins and DNA. Furthermore, it is instrumental in wound healing processes, cellular signaling, and division. Zinc plays a pivotal role in fostering healthy growth and development throughout various life stages, including pregnancy, infancy, childhood, and adolescence, and it is integral to the sense of taste.
In terms of bodily composition, the total zinc content averages about 1.5 grams in women and 2.5 grams in men, predominantly stored within skeletal muscle and bone tissues. [1.1]
Zinc is considered “essential” because human body cannot produce it on its own [2.1].
What does zinc do?
Zinc is an indispensable mineral that plays a crucial role in a wide array of physiological processes in the human body. Here's a more detailed examination of some of its primary functions [2.2]:
- Gene Expression [2.12].
- Enzymatic Reactions [2.12].
- Immune Function [2.12].
- Protein Synthesis [2.12].
- DNA Synthesis [2.12] .
- Wound Healing [2.12].
- Growth and Development [2.12].
Zinc is also an antioxidant [3.1] (Antioxidants are molecules that combat free radicals, which are are compounds that can inflict damage when their concentrations in the body exceed safe limits.) [4.1]
What are the benefits of zinc in human body.
Zinc is associated with reducing inflammation, enhancing immune health, decreasing the risk of age-related diseases, accelerating wound healing, and alleviating acne symptoms [2.2].
In details:
Zinc in Wound Healing Acceleration [2.3]
In medical settings, zinc is employed to treat burns, certain types of ulcers, and other dermal injuries due to its pivotal roles in collagen synthesis, immune function, and inflammatory response. Notably, the skin contains about 5% of the body's total zinc content. While zinc deficiency can impede wound healing, zinc supplementation can expedite wound recovery.
Potential Reduction in Age-related Disease Risk by Zinc [2.4]
Zinc has been suggested to significantly diminish the risk of age-associated diseases, including pneumonia and age-related macular degeneration (AMD). This is attributed to its capacity to alleviate oxidative stress and amplify immune responses, especially enhancing the activities of T-cells and natural killer cells, which are instrumental in safeguarding against infections. In some older studies, elderly individuals who consumed zinc supplements manifested an enhanced response to influenza vaccinations, diminished risk of pneumonia, and augmented cognitive functions.
Potential Acne Treatment via Zinc [2.5]
Acne, impacting an estimated 9.4% of the worldwide populace, is a prevalent dermatological condition. It arises due to the obstruction of oil-producing glands, bacterial presence, and inflammation. Research indicates that both topical and oral zinc regimens may treat acne effectively by curbing inflammation, inhibiting P. acnes bacterial growth, and suppressing sebaceous gland activities. Notably, individuals with acne frequently exhibit reduced zinc levels, suggesting that supplementation might ameliorate symptoms.
Anti-inflammatory Effects of Zinc [2.6]
Zinc has demonstrated the capability to attenuate oxidative stress and diminish the concentration of specific inflammatory proteins. Chronic inflammation, often instigated by oxidative stress, is implicated in numerous chronic ailments, including cardiovascular diseases, malignancies, and cognitive decline.
Zinc Deficiency
Severe zinc deficiency, while uncommon, can manifest in individuals with certain genetic mutations, breastfeeding infants with mothers deficient in zinc, individuals with alcohol dependencies, and those on specific immune-suppressing medications. [2.7]
Manifestations of a severe zinc deficiency include [2.8]:
- hindered growth and development.
- lag in sexual maturity.
- skin rashes
- chronic diarrhea.
- compromised wound healing.
- behavioral disturbances.
Approximately 2 billion individuals globally are believed to have a zinc deficiency resulting from insufficient dietary consumption. [2.9]
Risk factors
Individuals susceptible to zinc deficiency encompass the following groups [2.10]
- Individuals diagnosed with gastrointestinal conditions such as Crohn’s disease.
- Practitioners of vegetarian or vegan diets.
- Pregnant or lactating women.
- Older infants receiving exclusive breastfeeding.
- Patients with sickle cell anemia.
- Those experiencing malnutrition, including cases of anorexia or bulimia.
- Individuals with chronic kidney disease.
- Individuals diagnosed with alcohol use disorder.
Detecting zinc deficiency through laboratory tests is challenging because of the body's stringent regulation of zinc levels. Consequently, deficiency may be present even if test results suggest adequate levels. [2.11]
Sources of zinc
Meat, poultry, and seafood are significant sources of zinc. While plant-derived foods such as legumes and whole grains also provide zinc, they contain phytates that may reduce the mineral's absorption [5.1].
Sources of zinc include [5.2]:
- Shellfish: oysters, crab, lobster
- Beef.
- Poultry.
- Legumes.
- Nuts and seeds.
- Whole grains.
- Fortified breakfast cereals.
Supplements
Zinc can be found in standalone supplements, supplements combined with other elements, and numerous multivitamin/multimineral products. Various forms of zinc, such as zinc sulfate, zinc acetate, and zinc gluconate, can be present in these supplements. 'Nutritional Facts' section on a dietary supplement label specifies the quantity of elemental zinc, rather than the weight of the complete zinc compound.
Zinc absorption rates from supplements with zinc citrate or zinc gluconate are comparable, around 61% in young adults; for those with zinc oxide, the absorption rate is 50%. [1.2].
How to intake zinc
The daily zinc requirement varies based on age. The average daily recommended quantities for various age groups are provided in milligrams (mg) [6.1].
| Age | RA |
| Birth to 6 months | 2 mg |
| Infants 7–12 months | 3 mg |
| Children 1–3 years | 3 mg |
| Children 4–8 years | 5 mg |
| Children 9–13 years | 8 mg |
| Teen males 14–18 years | 11 mg |
| Teen females 14–18 years | 9 mg |
| Adult males | 11 mg |
| Adult females | 8 mg |
| Pregnant teens | 12 mg |
| Pregnant adults | 11 mg |
| Breastfeeding teens | 13 mg |
| Breastfeeding adults | 12 mg |
(data source: NIH for consumers)
Daily upper limits for zinc encompass intake from all sources, including foods, beverages, supplements, and medications. The subsequent chart delineates the limits for different age groups. It should be noted that these upper limits are not applicable to individuals consuming supplemental zinc for medical purposes under physician supervision [6.2].
| Age | RA |
| Birth to 6 months | 4 mg |
| Infants 7–12 months | 5 mg |
| Children 1–3 years | 7 mg |
| Children 4–8 years | 12 mg |
| Children 9–13 years | 23 mg |
| Teen 14–18 years | 34 mg |
| Adults | 40 mg |
(data source: NIH for consumers)
Takeaway
Zinc is an essential mineral, intrinsically present in many foods and accessible as a dietary supplement. Its importance in cellular metabolism, immune function, protein and DNA synthesis, and overall health cannot be overstated. With roles ranging from ensuring gene function to aiding wound recovery, zinc is paramount in maintaining the body's physiological balance.
Several benefits are associated with zinc, including its potential in reducing inflammation, boosting immune health, diminishing the risk of age-related diseases, promoting wound healing, and possibly treating acne. However, despite its myriad of benefits, zinc deficiency is an issue that affects approximately 2 billion people globally. Various factors, including diet and certain medical conditions, can influence one's zinc levels.
The integration of zinc into daily diets, either through natural food sources or supplements, is necessary to ensure optimal health. However, intake must be regulated based on age, with due consideration to avoid overconsumption.
It's essential for individuals to recognize the significance of this mineral and the potential consequences of deficiency.
References
- Zinc: fact sheet [NIH for Professionals] URL: https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/ - 1 , 2
- Zinc: Everything You Need to Know [Healthline, 2022] URL: https://www.healthline.com/nutrition/zinc - 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11, 12
- What are the benefits of zinc for health [Medical News Today, 2023] URL: https://www.medicalnewstoday.com/articles/263176 - 1 ,
- Antioxidant explained [Healthline, 2023] URL: https://www.healthline.com/nutrition/antioxidants-explained - 1
- Zinc [Harvard.edu] URL: https://www.hsph.harvard.edu/nutritionsource/zinc/ - 1 , 2
- Zinc [NIH for consumers] URL: https://ods.od.nih.gov/factsheets/Zinc-Consumer/ - 1 , 2