Constantly chewing – could this be Pica?

You might think it’s just a habit, something they’ll grow out of. But when children constantly need something in their mouth, whether it’s chewing on their collars and cuffs and hoodie strings, sucking on their toys, crunching on ice cubes, or even eating sand, stones, paper or tissues – it could be a condition called Pica. And while it might seem harmless at first, Pica can lead to serious problems like choking, digestive blockages, or even poisoning if they’re drawn to eating things like batteries, paint chips or soil.

Here’s what most people don’t know: Pica is often your child’s body desperately signalling that it needs certain nutrients, especially zinc and iron. I discovered this with my own children when they were ruining every t-shirt they owned with soggy holes all over. Within days of topping up these essential minerals, the chewing stopped completely. Their bodies had been trying to tell me something all along, and once I listened and gave them what they needed, everything changed.

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What is Pica?

Pica is the medical term for always mouthing or putting non-food items in your mouth for at least one month. Now, if your baby or toddler is putting everything in their mouth, that’s completely normal and it’s how they explore the world in those early years. But when children over the age of two continue to regularly do this behaviour, or when it becomes more intense and focused on specific non-food items, that’s when we start to think about Pica. It’s not the occasional chew on the end of a pencil during homework, but it is a genuine compulsion to seek out and put things in their mouth that aren’t meant to be eaten.

Pica is particularly common in neurodivergent children, especially those with autism, ADHD or sensory processing differences. These children often have higher nutritional needs and may struggle to absorb certain minerals properly, which can trigger these cravings. But it’s important to know that Pica can affect any child, regardless of whether they’re neurodivergent or not. I’ve worked with countless families where a seemingly healthy, neurotyPical child has developed Pica simply because their body was running low on essential nutrients. The key is recognising the signs early and understanding what your child’s body is trying to tell you.

How can you tell if it is low iron or low zinc – or both?

Pica is often your child’s body’s way of trying to correct a significant nutrient deficiency, and understanding which nutrients are low can help you target the right solution for your child.

Signs your child might be low in iron
Look out for pale lower eyelids, pale skin overall, and a child who seems constantly tired or lethargic. Low iron often shows up as poor appetite and frequent tummy aches. Your child might seem to have no energy for activities they once enjoyed. They might seem solemn, sad or withdrawn.

The good news is that iron levels can be checked through a simple blood test with your GP, giving you a clear answer about whether this is part of the picture. If a blood test sounds too daunting, the NatureDoc clinical team can run a hair test to assess iron status which is a less invasive way of looking at overall mineral levels.

Signs your child might be low in zinc
White flecks on the nails are a classic pointer towards low zinc. These children are often incredibly fussy eaters who avoid most fruits and vegetables and have a very narrow range of foods they’ll accept. This happens because zinc deficiency can affect their sense of smell, taste, and even how textures feel in their mouth making new foods seem genuinely unpleasant to them. They are often skinny kids who are on the small side. They are often quick to anger and the Pica also goes alongside explosive mood swings.

Zinc levels can be assessed through hair mineral analysis or urine tests, which can reveal deficiencies that don’t always show up in blood tests. As it stands, the NHS does not usually test zinc levels in children.

When it’s both iron and zinc
Many children struggling with Pica are actually low in both these vital minerals. These are often the kids with avoidant/restrictive food intake disorder (ARFID) and those who are extremely selective eaters who stick to a handful of safe foods and refuse almost everything else. It’s a frustrating cycle of low nutrients causing fussy eating, which leads to even lower nutrients, which makes the Pica worse. In the more high-needs or non-speaking kids this is where testing can be so valuable, so you really understand exactly which nutrients they might be lacking.

Why is it a problem?

As well as the risk of choking, Pica can lead to serious digestive blockages that may require surgery to open up your child’s abdomen and remove the item, or at the very least, strong laxatives to help clear their system. Batteries and magnets pose particularly serious risks if swallowed. Batteries can cause internal burns, while multiple magnets can stick together through the intestinal walls, Both require urgent medical attention, so go straight to A&E.

There’s another risk that many parents don’t know about, and that is that Pica can expose your child to lead toxicity, which can reduce their IQ and stunt their growth. Lead is still lurking in some children’s toys, old household paint, and even in garden soil. And where it gets particularly concerning is that lead exposure can actually cause anaemia, which triggers Pica in the first place. So you end up in a dangerous loop where low iron levels lead to Pica, Pica leads to eating soil or chewing painted surfaces, and then lead toxicity causes more anaemia, and the Pica gets worse. You can learn more about this in this Financial Times Toxic Legacy podcast, which I was involved in.

When children are low in zinc and iron, their bodies can’t function properly, and this affects everything from their immune system to their brain development. Low zinc impairs their sense of taste and smell, making healthy foods seem yucky, so they eat even less of the nutrients they desperately need. Meanwhile, low iron leaves them too tired and lethargic to want to eat much at all, and can affect their ability to concentrate and learn at school.

The longer these deficiencies go untreated, the further behind they fall. This is not just nutritionally, but developmentally and academically too. And all the while, the compulsion to chew and mouth non-food items continues, putting them at risk every single day.

I know this sounds overwhelming, and if you’ve been watching your child struggle with Pica, you’ve probably felt worried and helpless. But here’s the encouraging truth that once you identify and address the underlying nutrient deficiencies, you can break this cycle and help your child thrive. Many parents I’ve worked with have seen dramatic improvements within just days or weeks of getting the right nutrients on board.

It can happen in pregnancy too

Pica is common in pregnancy, too, and pregnant women who are low in iron or zinc can start to crave all sorts of things, from crunching on ice to coal. This is because risk of anaemia and low iron is very common in pregnancy. Nutrients can also get easily depleted if morning sickness leads to vomiting, and especially so in those women suffering from extreme morning sickness called Hyperemesis gravidarum. It is important to correct these during pregnancy as iron and zinc are important for both the baby’s development and for the mother’s recovery from the birth and reduces risk of post-natal depression.

Why do we get zinc & iron deficiencies?

Firstly, many kids (and some adults too) don’t eat enough zinc and iron-rich foods these days – think eggs, salmon, prawns, milk, chickpeas, pumpkin seeds and dates for zinc; and liver, red meat, eggs, spinach, lentils, sesame seeds, apricots and molasses for iron. Vegetarians and vegans are more likely to develop iron and zinc deficiencies, as it is harder to get enough of these in a plant-based diet and so it’s important to learn how to optimise the iron and zinc when eating a plant-based diet.

Children need A LOT more zinc when they are going through a growth spurt and during puberty and it’s sometimes very tricky to keep up, even with the best diet! They need zinc to help with growth and for the hormonal changes they go through during adolescence.

Also, some children struggle to absorb nutrients properly, even when they’re eating all the right foods. If your child has digestive issues like reflux, H. pylori infection, SIBO, coeliac disease, parasites or has had salmonella, their gut may not be able to absorb iron and zinc effectively. In these cases, simply adding more food or supplements won’t be enough and you will need to address the underlying gut problem first.

This is where stool testing and screening for infections, inflammation and malabsorption can be extremely helpful, especially if they are not growing or have a developmental delay. There are also genetic variations and other metabolic issues which can predispose kids to low zinc and iron levels and again these are things that we can investigate for you at our NatureDoc clinics.

Another emerging theory of why Pica and other eating disorders centred around distorted oral sensitivity happen, is the presence of chronic low-grade arsenic toxicity. A build-up of arsenic can affect gastric health (leading to poor secretion of gastric juices which are meant to rev up one’s appetite). Arsenic can also affect the neurological system which can lead to olfactory dysfunction, due to its effect on the sense of smell, taste as well as texture perception. This can lead to food refusal alongside the chewing or mouthing of non-food items.

Rice that has not been soaked and washed properly as well as gluten-free foods, rice cakes and rice milk pose a risk for high arsenic exposure. Equally, eating too much non-organic poultry (such as chicken nuggets) and non-organic fruit/fruit juice can lead to excess arsenic accumulating in the body. Both arsenic and lead toxicity can be identified through the hair mineral analysis we offer.

What you can do to help your child’s Pica?

Start by getting more zinc and iron into your child’s diet through food. Think red meat, chicken, eggs, beans, lentils, seeds (especially pumpkin seeds for zinc), and green veggies. Try giving them these foods at least twice a day, as even small amounts add up.

If your child is a fussy eater (which, as we’ve discussed, often goes hand-in-hand with these deficiencies), don’t worry about perfect meals. A bolognese sauce, some hummus with breadsticks, or even a smoothie with added seeds can all help boost their levels.

To speed things up (or if they simply won’t eat these foods), then add in a good-quality iron and zinc supplement. For most children, you’re looking at 7-11 mg of iron daily and 3-11 mg of zinc (or 15 mg for children over 12). Within days of giving these two minerals, you might notice the chewing slows up and their energy picks up.

If testing shows your child has a significant deficiency, they may need higher doses for a while, and that’s where working with your GP or a NatureDoc nutritional therapist can be really helpful to get the amounts right and monitor their progress. The key is to start somewhere, even if it’s just adding one iron-rich meal and a few drops of zinc today.

Round up

If your youngster is putting everything in their mouth and you’re spending every waking moment on high alert, we know how hard that can be. So many families are living this exhausting reality right now, and constantly watching to make sure nothing dangerous gets swallowed.

What’s important to remember is that Pica is often your child’s body’s way of showing you they have deficiencies in zinc and iron, two key nutrients that directly shape their development and eating patterns. Sorting out these nutritional gaps is an essential first step, and it’s safe to give daily for 3 months without testing if you follow the label instructions.

If the behaviour continues or you sense something deeper is going on, then our NatureDoc clinical team is here to help. We work with families one-to-one, running thorough nutritional and gut microbiome testing to get to the actual root of what’s affecting your child’s health. From there, we build a personalised health plan designed specifically for them. And we keep digging until your child finds real relief from being trapped in the Pica cycle.

Ask me what supplements can help… or anything else!

NB. This post is updated from the original post from 22 November 2020.