By: Patience Lister
How often do you think about the zinc in your diet? For many of us, it’s not often enough. Zinc plays a central role in immune function. So when you’re looking for additional support, zinc, along with vitamin C and echinacea, should be top of mind.
Zinc is an essential trace mineral – some consider it to be the most important trace element in the body. We need zinc in small concentrations to stay healthy, but because it’s not easily stored, we need to consume it daily.
As a catalyst, zinc plays a big part in many of the body’s biochemical reactions, including cellular metabolism and maintaining the function of over 200 enzyme activities. Zinc is also a structural element that is needed for normal growth and development throughout life, with roles in protein and DNA synthesis, wound healing, and connective tissue formation for healthy bones, skin, hair, and nails. In addition, zinc plays a regulatory role in balancing the conditions both inside and outside of cells as well as nerve transmission.
With so many important roles in the body, it’s no wonder that zinc plays a central part in immune function.
Zinc’s role in immunity
When your diet is low in zinc, it leaves you more susceptible to pathogens, such as viruses and bacteria. What’s more, a recent review of clinical trials concluded that zinc is one of the few supplemental nutrients that can be taken to shorten the duration of the common cold, helping to reduce symptoms by an average of 2.25 days. This is because zinc is involved in both the innate and adaptive immune systems.
Zinc plays an important role in the activity of white blood cells involved in protecting us from infection. It’s also needed for the production and activity of macrophages that detect and destroy pathogens, antibody production, and immune cell messengers called cytokines. A placebo-controlled clinical study found that supplementing zinc-deficient nursing home residents with a daily zinc supplement increased their T-lymphocyte [ST1] (a white blood cell) levels by 47%.
Zinc is also needed for effective wound healing and helps maintain the structural integrity of protective barriers that keep infectious microorganisms out, such as the skin and linings of the gastrointestinal and respiratory tracts. As an antioxidant, it protects tissues from oxidative stress and related inflammation. Because of this, zinc deficiency is believed to worsen symptoms of the inflammatory condition Crohn’s disease.
How much zinc do we need?
Despite its presence in many different types of food, around 10–35% of Canadians do not consume enough zinc. Frequent colds, slow wound healing, and loss of taste or smell are all symptoms that you may be mildly deficient in zinc; however, a lab test is the only way to confirm your levels. The chart below shows the recommended daily intake of zinc for people of various ages.
|Infants 0–6 months||2 mg|
|Children 7 months–3 years||3 mg|
|Children 4–8 years||5 mg|
|Children 9–13 years||8 mg|
|Boys 14–18 years||11 mg|
|Girls 14–18 years||9 mg|
|Men 19+||11 mg|
|Women 19+||8 mg|
|Pregnant women||11 mg|
|Breastfeeding women||12 mg|
Bioavailability is a key factor in many cases of zinc deficiency. Eating a vegetarian or vegan diet increases your risk of deficiency because the zinc found in plant-based foods has a lower bioavailability than the zinc found in animal products. The presence of phytate – an antioxidant compound found in whole grains, nuts, and seeds – in many cereals and legumes also lowers zinc absorption during digestion.
Certain health conditions can affect your risk of zinc insufficiency, including low stomach acid and digestive disorders, as well as being pregnant, breastfeeding, having [J2] sickle cell disease, and alcoholism. Older adults are also at risk of having insufficient levels of zinc.
Thankfully, you can normalize your zinc levels by increasing your intake of zinc-rich foods or through daily supplementation.
A daily dose of zinc
Zinc is found in a wide variety of foods from different food groups. You can help meet your needs by eating a balanced diet that includes plenty of whole grains, along with a range of fruit and vegetables, legumes, nuts, and seeds. Oysters, lean meats, and poultry are also fantastic sources.
Taking a daily zinc supplement is a convenient and reliable option for people with low stomach acid levels or digestive disturbances, as well as anyone with an inadequate mineral intake who needs help meeting their daily zinc requirements.[ST3] You can choose from various forms of supplemental zinc, including zinc citrate and zinc chelate tablets, as well as throat lozenges that combine zinc with echinacea and vitamin C.
Because there are side effects to overconsuming zinc, it is always important to consult a qualified health care practitioner before taking a daily supplement.
Part of your immune support plan
If you’re looking to prime your natural defenses and stay on track during the cold and flu season, don’t overlook the importance of zinc. As a central element for your body’s immune function, your zinc intake should be a top consideration in your immune support plan.
 Chasapis, CT, Loutsidou, AC. Zinc and human health: an update. Arch Toxicol. 2012; 86: 521-534.
 Wegmüller R, Tay F, Zeder C, et al. Zinc absorption by young adults from supplemental zinc citrate is comparable with that from zinc gluconate and higher than from zinc oxide. J Nutr. 2014; 144(2): 132-136.
 National Institutes of Health. Zinc. Health Professional Fact Sheet [Internet]. U.S. Department of Health & Human Services. Available from: https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/
 Shankar AH, Prasad AS. Zinc and immune function: the biological basis of altered resistance to infection. Am J Clin Nutr. 1998; 68:447S-463S.
 Wang MX, Win SS, Pang J. Zinc supplementation reduces common cold duration among healthy adults: A systematic review of randomized controlled trials with micronutrients supplementation. Am J Trop Med Hyg. 2020; 103(1):86-99.
 Barnett JB, Dao MC, Hamer DH, et al. Effect of zinc supplementation on serum zinc concentration and T cell proliferation in nursing home elderly: a randomized, double-blind, placebo-controlled trial. Am J Clin Nutr. 2016; 103(3):942-951.
 Siva S, Rubin DT, Gulotta G, et al. Zinc deficiency is associated with poor clinical outcomes in patients with inflammatory bowel disease. Inflamm Bowel Dis. 2017; 23(1):152-157.
 Health Canada. Canadian Community Health Survey. Do Canadian Adults Meet Their Nutrient Requirements Through Food Intake Alone? [Internet]. Government of Canada. Canada.ca. 2012. Available from: https://www.canada.ca/en/health-canada/services/food-nutrition/food-nutrition-surveillance/health-nutrition-surveys/canadian-community-health-survey-cchs/canadian-adults-meet-their-nutrient-requirements-through-food-intake-alone-health-canada-2012.html
 Health Canada. Guidelines for Canadian Drinking Water Quality: Guideline Technical Document – Zinc [Internet]. Government of Canada. Canada.ca. 2020.. Available from: https://www.canada.ca/en/health-canada/services/publications/healthy-living/guidelines-canadian-drinking-water-quality-guideline-technical-document-zinc.html