The importance of zinc across all ages: A guide for parents and women

Zinc is an essential nutrient that plays a critical role in our bodies from infancy through adulthood. It’s considered essential because our bodies cannot produce or store zinc on their own 

We get it regularly through our diets. Yet many people, including women and children, may not be getting enough. In clinical practice, if I review 40 labs in a week, 2 people will have optimal levels of zinc.

In fact, national nutrition surveys suggest that a significant portion of New Zealanders have inadequate zinc intakes (around one-quarter of adults), with certain groups like older men showing especially high rates of insufficiency. This article explores why zinc is so vital for health, how factors like stress and local soils can affect zinc levels, who is most at risk of deficiency, and how to ensure you and your family meet daily zinc needs.

Why zinc is an essential nutrient

Zinc is involved in hundreds of biological processes that keep us healthy. It is a structural component or co-factor for over 300 enzymes, which means it helps catalyse reactions in the body related to metabolism, cell division, DNA synthesis, and more. Here are some of the key functions of zinc:

• Immune function: Zinc is crucial for a strong immune system. It helps develop and activate T-lymphocytes and other immune cells. One of the first signs of zinc deficiency is often a weakened immune response or more frequent infections. Even mild zinc deficiency can impair immune defences, which is why adequate zinc is important for fighting off colds and other illnesses.

  
  

• Cell growth and wound healing: This mineral is necessary for normal cell growth and repair. Zinc supports healthy skin and is well-known for aiding wound healing. If you get a cut or injury, zinc is needed to help the skin and tissues regenerate (you can self-diagnose zinc deficiency at home, when your cuts or wounds take a while to heal). It also plays a role in blood clotting during wound healing. Children and pregnant women especially need zinc for proper growth and development, as zinc drives cell division and tissue formation. Long-term zinc deficiency in kids can lead to stunted growth and developmental delays.

  
  

• Hormonal balance and reproduction: Zinc is involved in the production and regulation of many hormones. For example, it’s essential for reproductive health in both sexes. In men, zinc is required for testosterone production and prostate health, and low zinc is associated with fertility issues. In women, zinc helps with the utilisation of estrogen and progesterone; sub-optimal zinc levels are linked to hormonal imbalances like higher estrogen levels, disrupted ovulation, and fertility challenges. Adequate zinc during pregnancy is vital it supports fetal growth and may influence birth outcomes (even mild zinc deficiency in pregnancy has been associated with suboptimal outcomes).

  
  

• Thyroid function and other roles: Zinc contributes to healthy thyroid function, which controls metabolism. It’s also important for our senses of taste and smell; a loss of taste or smell can sometimes indicate a zinc deficiency (you will often find children who are deemed “fussy eaters” actually are deficient in zinc). If your child has additionally, zinc has roles in cognitive function and mood regulation (for instance, it’s involved in neurotransmitter production like serotonin). Because zinc is so broadly needed, a deficiency can manifest in diverse ways, such as hair loss, skin lesions, loss of appetite, diarrhea, and delayed sexual maturation in severe cases.

Zinc and stomach acid: A two-way street

Another overlooked but critical relationship is between zinc and stomach acid. Zinc is required to produce hydrochloric acid (HCl) in the stomach, the acid that helps break down food and absorb nutrients, especially minerals and protein.

Low stomach acid (hypochlorhydria) is surprisingly common and can lead to bloating, reflux, poor digestion, malabsorption of our food and even further zinc deficiency, since HCl is essential for absorbing zinc efficiently. This creates a vicious cycle: low zinc leads to low stomach acid, and low stomach acid leads to poor zinc absorption. People with a history of reflux, chronic stress, or long-term use of acid-blocking medications (like PPIs) are particularly at risk.

Supporting stomach acid production naturally with practices like eating slowly, managing stress, taking betaine HCL (only under the care of a practitioner) and possibly supplementing with zinc under guidance can break this cycle and significantly improve digestion and nutrient uptake.

How stress and illness deplete zinc

Maintaining zinc levels is not just about diet and supplements. LIFESTYLE plays a major role.

Stress, intense physical activity, and illness can all deplete zinc or increase the body’s demand for it. In stressful situations or during acute trauma and infections, the body’s plasma zinc levels tend to drop. Stress hormones and inflammatory responses may redistribute zinc in the body and increase zinc losses. For example, studies show that severe psychological stress can cause zinc to be lost rapidly through urine. When you’re recovering from surgery, going through emotional stress, or doing high-endurance exercise, your body uses up available zinc to heal tissues and buffer the stress response. Long-term endurance training has been associated with significantly reduced zinc levels in athletes compared to non-athletes, likely due to zinc being lost through sweat and the increased turnover from exercise.

Illness can further deplete zinc status. The immune system uses zinc during an infection, so fighting off a sickness (like a prolonged cold or flu) can lower zinc (sidenote: what happens when you have a lingering virus in your body, like Epstein-Barr virus that is always there, draining your zinc levels. Or you have cold sores, also a virus).

In fact, a feedback loop exists: low zinc status makes it harder to resist and recover from infections, and infections in turn can utilise and reduce zinc. Certain chronic illnesses also impair zinc absorption or increase losses. For instance, gastrointestinal disorders (like Crohn’s or coeliac disease) can reduce zinc absorption, and chronic liver or kidney diseases can lead to increased zinc excretion. High alcohol intake is another factor – alcohol can both diminish zinc absorption and increase its excretion. Because our bodies don’t have a deep storage reserve for zinc, it’s important to top up our zinc through diet or supplements. Especially during times of stress, heavy exercise, or illness.

The zinc gap: Soil and diet in New Zealand and Australia

Aside from individual factors, the environment and local food supply play a role in our ZINC levels. Evidence suggests that soils in New Zealand and many parts of Australia are naturally low in zinc, meaning the crops grown in these countries soil have lower zinc content.

In New Zealand, for example, decades of intensive farming and natural soil composition have left soils depleted in minerals like zinc, so today’s vegetables may contain less zinc than in the past. Australian agricultural soils are also widely recognised as being deficient in zinc and other micronutrients. This soil zinc gap can trickle down to the food chain – grains, vegetables, and other produce grown in zinc-poor soil will inherently have lower levels of this nutrient.

For consumers, this means that even a “healthy” diet with plenty of local organic produce might not provide as much zinc as expected if the foods are grown in zinc-poor regions. The issue is compounded by modern dietary patterns. Many people today eat fewer zinc-rich foods like red meat and shellfish, and more processed foods or refined grains from which zinc has been removed during manufacturing.

In New Zealand, studies have noted that adolescent girls and women often have declining zinc intakes over time, partially due to eating less meat and seafood and older women also tend to consume inadequate zinc. Thus, both the food source (where and how it’s grown) and food choices influence zinc nutrition. Recognising this “zinc gap” is important, especially for those in NZ and Australia, so that families can adjust diets or consider supplementation if needed to meet zinc requirements.

Who is at risk of zinc deficiency?

Certain populations are at higher risk of zinc deficiency. These include:

• Pregnant and breastfeeding women: Pregnancy and lactation increase zinc requirements because zinc is needed for the growing fetus and is secreted into breast milk. Pregnant women need about 11 mg of zinc per day (vs 8 mg for other adult women), and breastfeeding women about 12 mg/day. If these higher needs aren’t met, mothers can become deficient, which may impact pregnancy outcomes or the zinc status of the. In fact, lactation can rapidly deplete a mother’s zinc stores if intake isn’t sufficient. Ensuring ample zinc is one reason prenatal vitamins and postnatal nutrition are so important.

• Infants and children: Zinc is critical for growth in infancy and childhood. Babies under 6 months get zinc from breast milk or formula, but after about six months of age, breast milk alone doesn’t provide enough zinc for an infant. Older infants need zinc-rich complementary foods (such as pureed meats) once they start solids. Toddlers and children are at risk if they are picky eaters or on limited diets. Growth spurts in adolescence also demand adequate zinc. Marginal zinc intake in kids can result in slowed growth and weaker immune function, so parents should ensure children eat a variety of zinc-containing foods.

• Vegetarians and vegans: People who follow vegetarian or vegan diets are more prone to low zinc status for a couple of reasons. First, plant-based foods have lower zinc bioavailability – even if total zinc content is moderate, compounds like phytates in legumes, whole grains, nuts, and seeds bind zinc and reduce its absorption. Second, vegetarians avoid major zinc sources like red meat and shellfish. As a result, vegetarians (especially those consuming mostly unrefined grains/legumes) may need to consume up to 50% more zinc than omnivores to compensate for lower absorption. For example, the nutrient reference values suggest strict vegetarians may require a higher intake to meet the same needs. Including eggs and dairy (for vegetarians), zinc-fortified foods, and using food preparation techniques like soaking or sprouting beans and grains can improve zinc uptake. But some vegetarians and vegans, particularly if pregnant or breastfeeding, should be vigilant and consider supplements if dietary intake is insufficient (consulting a healthcare professional).

• Older adults (elderly): The elderly are another at-risk group for zinc deficiency. As we age, appetite and food intake may decrease, and dietary patterns might shift to foods with less zinc. Additionally, older adults often have less efficient absorption and may have health conditions or medications that interfere with zinc status. Research indicates zinc intake tends to be low in many older people. A consequence is that low zinc in seniors can contribute to a decline in immune function (part of immunosenescence). Infections like pneumonia can be more common or more severe in zinc-deficient older individuals. Thus, ensuring sufficient zinc (through diet or supplements when necessary) is a key aspect of healthy aging.

These groups above are not the only ones others who might need extra zinc include people with malabsorption syndromes (e.g. inflammatory bowel disease), those with high alcohol consumption, and individuals with sickle cell disease or diabetes (these conditions can affect zinc metabolism). Women of all ages in New Zealand, in general, have been observed to have suboptimal zinc intakes, so it’s wise for women to pay attention to zinc, particularly during life stages of increased need.

Meeting daily zinc needs: Food and supplements

How much zinc do you need? 

Health authorities in Australia and New Zealand have established nutrient reference values (NRVs) that include recommended daily intakes for zinc. For adult women, the recommended dietary intake (RDI) is 8 mg of zinc per day, and for adult men, it’s 14 mg per day.

Requirements are higher during certain life stages: as mentioned, pregnancy requires about 10–11 mg (teen vs adult pregnancy) and lactation about 11–12 mg of zinc per day. Children need smaller amounts, increasing with age (for example, 3 mg for toddlers, 4–6 mg for young children, and 7–13 mg for teenagers, depending on sex). These recommended intakes are designed to cover the needs of the majority of healthy individuals. It’s also worth noting that an Upper Level (UL) for zinc is set at about 40 mg per day for adults.

The best way to meet your zinc requirement is through a balanced diet rich in zinc-containing foods. Zinc is found in both animal and plant foods, though it is more abundant and bioavailable in the animal-based sources. Excellent dietary sources of zinc include:

• Seafood (especially oysters): Oysters are the richest source of zinc, famously containing more zinc per serving than any other food. For example, 100g of oysters can provide around 50–70 mg of zinc, which is several times the daily requirement. Other shellfish like crab and mussels, as well as fish, also contribute zinc (though in lower amounts than oysters).

  
  

• Red meat and poultry: Meats such as beef, lamb, and to a lesser extent, pork and chicken, are high in zinc, and the zinc is readily absorbed. A 100g serving of beef might provide roughly 8–12 mg of zinc, which goes a long way toward the daily target. Including lean red meat in the family diet once or twice a week can significantly boost zinc intake. Poultry (chicken, turkey) has moderate zinc content as well.

  
  

• Dairy products and eggs: Dairy foods like milk, cheese, and yogurt supply some zinc, and they can be useful, especially for vegetarians. Eggs also contain zinc. While these foods are not as zinc-dense as red meat or oysters, they can contribute to overall intake as part of a varied diet.

  
  

• Whole grains, nuts, seeds, and legumes: Plant-based foods such as beans, lentils, chickpeas, whole grain breads and cereals, nuts (e.g. cashews, almonds), and seeds (pumpkin seeds, sunflower seeds) contain zinc. For instance, a handful of pumpkin seeds or a cup of cooked lentils provides a few milligrams of zinc. However, remember that these also contain phytates, which inhibit some zinc absorption. Preparing these foods by soaking, sprouting, fermenting, or using yeast (as in bread) can reduce phytate content and make their zinc more available. Including vitamin C-rich foods in meals (like fruits or lemon juice in a bean salad) may also help improve mineral absorption.

  
  

In Australia and New Zealand, many people get a large portion of their zinc from meat and seafood. If you consume a well-balanced diet that includes protein sources and whole foods, you are likely to meet your zinc needs as long as your body isn’t ALREADY DEPLETED IN ZINC. Vegetarians and vegans should be mindful to include zinc-rich plant foods at each meal and might benefit from the higher end of recommended intakes due to lower absorption. For example, a vegetarian woman might aim for 12 mg of zinc per day instead of 8 mg.

Conclusion

Zinc may not get as much spotlight as some other nutrients, BUT I’m here to say it SHOULD!!! ZINC is one of the first blood tests that I have run for my clients in clinic for years! It is so KEY to our overall VITALITY, not to mention all of the above reasons. For women, maintaining adequate zinc is important for everything from immune balance and skin health to fertility and healthy pregnancies. The challenges of modern life, stress, busy schedules, changing diets, and even the nutrient content of our soils mean we should be aware of zinc and not take it for granted. The good news is that with a balanced diet (and supplements when needed), zinc needs can be met. By including zinc-rich foods in your family’s meals and being mindful of the signs of low zinc, you can harness the benefits of this essential mineral for you and your loved ones.

Of course Bio Precision Nutrients can help you achieve optimal levels - click here to learn more.

References

• Nutrient Reference Values for Australia and New Zealand – Zinc (NHMRC/Ministry of Health NZ) healthify.nz and eatforhealth.gov.au

• Eat For Health (Australian Government) – Zinc fact sheet and recommendations eatforhealth.gov.au

• Ministry of Health NZ – Nutrient Reference Values and dietary guidelines (see Minerals – Zinc) healthify.nz

• Healthify NZ: Zinc – Overview of zinc’s role, requirements, and risk factors healthify.nz

• Better Health Channel (Victoria, AU): Information on zinc in diet and health healthyfood.com

• Williden, M. (2023). “Think Zinc.” NZ Herald – Article on zinc deficiency in NZ diet and soil nzherald.co.nz.

• Cochrane Database of Systematic Reviews: Zinc supplementation and the common cold (for those interested in zinc’s effects on immunity and cold duration) healthify.nz