Think Zinc

Mindd Foundation

What do children with acne, recurrent ear and chest infections, irritability and a poor appetite have in common? The latest research shows that even children with autism may be affected by the same problem: They may all not be getting enough zinc from their diet.

Zinc is an essential mineral just like iron that we are supposed to absorb from our food. Over 100 enzymes in humans are dependent on zinc for their activity, and because these enzymes are involved in so many different metabolic pathways in the body, the signs and symptoms of zinc deficiency are extremely diverse, ranging from suboptimal immune health, to poor growth, skin healing, mood regulation, appetite and neurodevelopment. Zinc is along with iron the most highly concentrated mineral in our brains. And it is unfortunately extremely low in Australian and New Zealand soils and therefore it is low in crops grown in these soils; so low in fact that most children are not getting enough of it in their diet.  A study from 2000 in the Journal of Nutrition concluded that only 18.9% of children aged 1-3 years and only 50.5% of children aged 11-18 years had adequate zinc intake. Since then our soil quality has not improved and there is no indication that our children’s zinc status has improved. Worldwide it is estimated that about 25% of children are zinc deficient.

Farmers give their animals zinc supplements, as they know that they would otherwise get sick or die. This is one of the few instances where we treat our animals better than our children.  Today I am making a case for why most children may need a zinc supplement, just as our cattle and sheep do.

Children who do not get enough zinc in their diet can become stunted (ie end up short) and suffer from recurrent infections, even anaemia – this has been well described in developed countries. But what about our local children? They may not be actually deficient, but often have suboptimal levels because the vegetable and grains grown on our soils do not contain much zinc. Suboptimal zinc intake is increasingly seen as a growing public health issue. I see too many children with recurrent infections and always test their zinc level. Most of the time it is low or at the low end of what is considered normal. Interestingly the laboratories’ normal range of zinc in Australia and New Zealand is way lower than in other countries. This reflects the average found in the population, not the optimal range. The optimal range is likely to be around 16-18 umol/L (our Australasian labs’ normal range is about 12 to 18).

Researchers in New Zealand have been looking into zinc deficiency for many years: they were wondering why Auckland was the cellulitis (skin infection) capital of the developed world – with levels as high as some of the poorest developing countries. And they found that the children who kept being admitted to hospital for IV antibiotics were in fact zinc deficient and that once they were given zinc supplements, the skin healed and no new infections happened.  It was that simple!

Bronchiectasis (an infection that over time destroys the lungs) is another example of a disease generally rare in developed countries, but common in New Zealand children. Just as with skin infections, the children with bronchiectasis had low zinc levels and their health improved once they were given a zinc supplement.

What about the effect of zinc on our mental health? The key findings of several studies indicate that zinc status has a direct impact on mood. Low levels have been shown to be associated with depression, stress, anxiety, and aggression, as well as impaired development in children. What’s even more interesting is that zinc supplementation has been shown to be beneficial for stress, anxiety, mental health, vigour, and cognitive performance in healthy subjects.

Many families struggle with the low mood of their children – they are irritable, get angry quickly and melt down all too regularly. Life could be so much more pleasant if only the kids were happier. Zinc is needed for a calm and happy mood. Low zinc creates high copper in the blood – the two minerals go like a see saw – when one is down the other is up. Low zinc gives you a low frustration tolerance and makes you irritable and the high copper makes you explosive. Not a fun combination. But just by giving enough zinc to get it to normal levels, the copper drops into the normal range as well and your child feels more even and happier and the tantrums become less frequent.

The University of Auckland is currently studying zinc as a treatment for genetic variations associated with autism. An abnormal protein called shank 3, associated with autism and schizophrenia, can cause problems with brain cell communication and it looks like this can be improved with zinc.

I have seen many children with low moods, autism and ADHD improve in terms of their mood and development when their zinc levels were boosted into the optimal range.

Zinc needs are highest when children go through growth spurts – that may be why toddlers and teenagers are the most volatile to deal with!

Zinc is also needed to eliminate toxins from our bodies. You need 4-6 molecules of zinc to get rid of one molecule of a toxin, whether that be lead (from your outdoor paint dust), mercury from the tuna sandwich you had for lunch or an orange lolly (with the artificial colouring E102 which just like other toxic chemicals needs zinc to be excreted). So next time your child melts down after having a bright orange drink: think zinc. His levels just dropped abruptly because his body is working hard on getting rid of a poison. If your child had had adequate zinc stores to begin with and no genetic variations that make him more susceptible to low zinc levels, his or her reaction may not have been so intense.

If your child is irritable or gets sick frequently, you may want to have his or her zinc level checked. White spots on the nails are a tell-tale sign of low stores of zinc. Some people use a taste test – you swish a zinc solution in your mouth and if you are low in zinc you cannot taste it (because your taste buds do not work properly); if you have good zinc levels and hence healthy taste buds, you spit out the awful brew immediately.  For a more accurate assessment get a blood test (plasma zinc or red blood cell mineral analysis are considered the most useful).

My preferred source of all nutrients is of course real food. Unfortunately, there are not many foods that are rich in zinc in Australia and New Zealand. Oysters are an exception, but they are also high in salmonella and therefore not a great option, especially for children who already struggle with a weak immune system.

All good multivitamins/multiminerals contain zinc – and that is a good start for treatment, as you are unlikely to overdose on such a small dose. If bigger doses are needed, supplement under the guidance of a nutritionally trained doctor, nutritionist, or naturopath – start with a small dose and slowly increase to the prescribed one. Retest the level every few months as it is possible to overdose. The first symptom of too much zinc is usually nausea; it can also lead to anaemia due to the copper falling too low.

So in summary:

If your child gets sick often, is irritable, has poor skin healing or acne or is a picky eater – get him or her checked out by a nutritionally trained health practitioner. The answer may be simple. Think zinc!


Dr Leila Masson is an integrative paediatrician in Bondi Beach and the author of “Children’s Health A-Z for New Zealand Parents”. A book packed with information on how to raise healthy children and treating their illnesses naturally, quickly and effectively. The book is just as useful for Australian parents and families around the world as for those in NZ.



Briefel RR et al. Zinc Intake of the U.S. Population: Findings form the Third National Health and Nutrition Examination Survey, 1988-1994. J Nutr. 130: 1367S-1373S (2000)

Javadmoosavi et al. Comparison of the serum concentration of zinc in patients with bronchiectasis and control group. Iran Red Crescent Med J. 2013 Jul;15(7):587-9. doi: 10.5812/ircmj.7735. Epub 2013 Jul 5.

Lai J et al. The efficacy of zinc supplementation in depression: Systematic Review of randomized controlled trials. Jounral of Affective Disorders 136 (2012) e31-e39 (2016)

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