Iron plays a crucial role in a child’s development – supporting brain growth, energy production, immune strength, and the transport of oxygen throughout the body. Yet despite its importance, iron deficiency remains the most common nutrient deficiency in children. When iron levels drop below what a growing body needs, the consequences can be significant – from persistent tiredness and more frequent infections, to poor concentration, behavioural shifts and, in more serious and prolonged cases, developmental delays.

Recent data suggests that around 75% of infants aged 6 to 12 months, and a quarter of toddlers aged 1 to 2 years in Australia aren’t meeting their recommended iron intake. That’s a concerning number of little ones who may be starting life with less of this essential mineral than their bodies truly need.

So what increases a child’s risk of developing low iron? Let’s take a look at some of the most common contributing factors – drawn from both the scientific literature and my clinical experience.

1. Low maternal iron stores at birth

The iron status of a newborn is closely linked to the mother’s iron levels during pregnancy. If a woman enters pregnancy with low iron stores – or develops iron deficiency during gestation – the baby is more likely to be born with reduced iron reserves. Babies are born with their own supply of stored iron, intended to sustain them for the first 4–6 months of life since there is no iron in breast milk. But if those stores are low at birth, it can leave the infant vulnerable to early depletion – particularly without timely introduction of iron-rich solids at around six months of age. 

This is why maternal iron sufficiency before and during pregnancy is so important – not just for mum’s health, but for the long-term wellbeing of her baby.

2. Born premature or low birth weight 

Babies born prematurely or with a low birth weight are at higher risk of iron deficiency, simply because they’ve had less time to build up their stores while in the womb. These bubs need closer monitoring and may require earlier support to ensure their growing bodies have enough iron. Your paediatrician will guide you with this.

3. Delayed or inadequate introduction of iron-rich foods 

By around six months of age, a baby’s iron stores begin to run low and need to be replenished through food. This is when iron-rich solids become essential – but for various reasons, such as picky eating, food sensitivities or a lack of awareness, some infants don’t receive enough.

What’s particularly tricky is that iron deficiency can actually drive appetite issues, especially a reluctance to eat iron-rich foods like red meat. So once a deficiency is present, it can create a vicious cycle that’s tricky to break. Introducing iron-rich foods early – and persistently offering them, even when initially refused – can go a long way toward protecting a child’s iron status. Some options include cooked and/or pureed red meat, mashed legumes (like lentils or black beans) or soft boiled eggs. 

4. Excessive intake of dairy milk or formula 

One of the most overlooked risk factors for iron deficiency in toddlers is high milk intake – whether from cow’s milk or formula. More than 500ml per day can too easily crowd out other foods. Milk contains calcium which competes with iron for absorption in the gut – and since it’s a bigger substance, it usually wins out. It’s also filling, which means children may eat less iron-rich food if their tummies are already full of milk. If your child is over 12 months, separate milk-based meals from those that contain iron as much as possible and encourage a wide variety of whole foods, particularly those rich in iron.

5. Other factors to consider 

• Rapid growth in infancy and adolescence increases iron demand.
• Fussy eating or limited diets can reduce intake of iron-rich foods.
• Chronic gut issues, including inflammation or inadequate stomach acid, can impair iron absorption – especially if there's a history of recurring antibiotic use or undiagnosed food sensitivities.
• Certain gut infections, such as Helicobacter pylori, can disrupt robust stomach acid production and interfere with iron uptake. Plus, the organism takes the iron consumed for itself.
• Plant-based diets require special attention. Non-haem iron (from plant foods) is absorbed less efficiently than haem iron (from animal foods), so children following vegetarian or vegan diets typically need 1.8 times the recommended intake to meet their needs.

What to do if you’re concerned

If you suspect your child may be low in iron, look out for common signs such as fatigue, pale skin, irritability, frequent colds, or poor appetite. I’ve written more extensively about these symptoms in this checklist which I used to help identify childhood iron deficiency in clinic. If you’re still unsure, speak with your healthcare provider. Simple “iron studies” blood tests, that include ferritin (your child’s stored iron) can offer clarity. If levels are low or low end normal, your child may require supplementation alongside dietary changes to restore iron status.

Remember, prevention is always easier than treatment. Prioritising iron-rich foods from six months of age, supporting maternal iron during pregnancy and staying mindful of milk intake can give your child a strong foundation for growth, development and vitality. Because when a child has the energy to run, play, learn and explore, everything changes – and iron is often the key to unlocking that full potential.