This includes immunity, cell growth, hormone regulation, wound healing, and metabolic function. Because the body does not store zinc well, you need a reliable supply from diet or supplements. (NIH ODS, 2025).

Zinc contributes to hundreds of biochemical processes:

• Immune function: Zinc is required for normal development and function of immune cells like neutrophils and natural killer cells. (NIH ODS, 2025)

• Tissue growth and repair: Zinc supports DNA and protein synthesis, which is essential for healing and cell regeneration. (NIH ODS, 2025)

• Enzyme reactions: Zinc is part of enzymes involved in digestion, metabolism, and antioxidant processes. (NIH ODS, 2025)
• Hormone regulation: Zinc affects thyroid hormones and testosterone, influencing metabolism and reproductive health. (NIH ODS, 2025)

Good food sources include:
• Oysters (highest food source)
• Meat, poultry, fish
• Dairy products
• Legumes, nuts, seeds, whole grains (note: absorption from plant foods is lower due to phytates) (NIH ODS, 2025)

Explore a full list of zinc-rich foods and serving amounts under the "Food" heading.

Zinc deficiency is more common than many people think, especially in populations with low dietary diversity or high phytate intake (e.g., vegetarian/vegan diets). Some signs include:
• Frequent infections or slow recovery
• Poor wound healing
• Changes in taste or appetite
• Hair thinning
• Skin rashes or dermatitis
• Fatigue (NIH ODS, 2025)

If you suspect low zinc, talk to a healthcare provider about testing or evaluation.

Zinc plays a critical role in immune system signalling and cell activity.

According to the U.S. National Institutes of Health, “Zinc deficiency impairs immune function, including reduced activity of immune cells and increased susceptibility to infection.”

Read more here.

Some intervention studies (especially in older adults) also show that zinc lozenges or supplements can reduce the duration and severity of common colds when taken at the onset of symptoms. (NIH ODS, 2025)

Most people can meet their zinc needs through a balanced diet. However, supplementation may be advised when:

• • Diet lacks animal protein (higher plant-based diets)

• • Absorption is reduced (e.g., gastrointestinal conditions)

• • Requirements are increased (e.g., pregnancy or infection)

• • Older age or chronic illness reduces intake or uptake (NIH ODS, 2025)
  
  

• Zinc supplements come in different forms - citrate, Polaprezinc (Zinc carnosine) and amino-acid chelates — with slight differences in absorption. All can be effective when taken at appropriate doses.

While zinc is essential, too much can cause harm:
• Taking more than the upper tolerable intake level of 40 mg/day can interfere with copper absorption and immunity.
• High doses can also cause nausea, cramps, and digestive upset.

Always consult a healthcare professional before starting a supplement, especially if you’re on medication or have chronic conditions. (NIH ODS, 2025)

Zinc isn’t a standalone “magic bullet.” It works in harmony with other nutrients (especially vitamins A, C, and B6) to support immune and metabolic health. Making sure you have enough zinc through diet and supplementation when needed is a smart, evidence-based strategy for resilient health.

AU.S. National Institutes of Health – Office of Dietary Supplements (ODS):
Zinc — Health Professional Fact Sheet https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional

World Health Organization (WHO): Vitamin and Mineral Requirements in Human Nutrition (2nd Edition)
https://www.who.int/publications/i/item/9241546123

Healthdirect Australia – Zinc Overview: Zinc and your health
https://www.healthdirect.gov.au/zinc