Iron deficiency in babies and toddlers

6-12 months · Health · Reviewed 18 June 2026 · All articles

Iron is one of the most important nutrients in early life and also one of the most commonly deficient. Around the world, iron-deficiency anaemia is the most prevalent nutritional deficiency in children under 5, according to the World Health Organization. Understanding why iron matters, which babies are most at risk, and how to make sure your child gets enough through food is one of the most practical things you can do to support their development.

This article draws on NHS and WHO guidance to explain iron's role, the risk periods for deficiency, the best food sources, and when to talk to a doctor.

Why iron matters so much in infancy

Iron plays a central role in the production of haemoglobin, the protein in red blood cells that carries oxygen around the body. When iron is insufficient, the body cannot make enough healthy red blood cells, leading to anaemia. In infants and young children, the consequences of iron deficiency go well beyond fatigue.

The first two years of life are a critical window for brain development. The brain grows faster in this period than at any other time, and iron is essential to this process. It is involved in myelination (the formation of the fatty sheath around nerve fibres that enables fast electrical signalling), neurotransmitter production, and the development of the prefrontal cortex, which governs attention, behaviour and cognitive function.

Research cited by the WHO shows that iron deficiency in infancy, even when not severe enough to cause obvious anaemia, can affect attention, memory, learning and social-emotional development in ways that may persist into later childhood. This is why catching deficiency early and preventing it through diet is so important.

Iron also supports immune function. Children who are iron-deficient tend to be more susceptible to infections. They may also show reduced physical stamina, poor appetite and, in more severe cases, delayed growth.

When the risk of deficiency is highest

Babies are born with a supply of iron that was transferred from the mother during pregnancy, particularly in the third trimester. For full-term babies born at a healthy birth weight, these stores typically last around 4 to 6 months.

This is one of the reasons that solid foods are recommended around 6 months: it is the point at which dietary iron needs to take over from stored iron. Once solids begin, the range and iron content of what a baby eats becomes very important.

Premature babies

Babies born before 37 weeks have had less time to build up iron stores in the womb. Premature babies, particularly those born before 32 weeks, are often prescribed iron supplementation from a few weeks after birth. Your neonatal or paediatric team will guide this: do not start iron supplements without medical advice.

Low birth weight babies

Babies with a low birth weight also tend to have smaller iron stores. If your baby was born small or if there were complications with the placenta, your health visitor or GP may want to monitor iron levels more closely.

The toddler years

The period between 12 and 24 months is another window of higher risk, for a different reason. Many toddlers go through a phase of drinking large amounts of cows milk. Milk is low in iron and, crucially, it can reduce the body's ability to absorb iron from other foods. Toddlers who drink more than around 400ml of cows milk per day are at significantly higher risk of iron deficiency. The NHS advises limiting cows milk as a drink to this amount from 12 months.

Fussy eating, which is extremely common in toddlers, can also reduce iron intake if the foods being accepted are mainly low in iron (such as bread, crackers and milk-based foods).

Recognising signs of iron deficiency

Iron deficiency develops gradually, and early stages often produce no obvious symptoms. As deficiency deepens, you may notice some of the following:

Tiredness and low energy: your baby or toddler may seem unusually lethargic or less active than usual.
Pale skin: pallor, particularly visible in the gums, inner eyelids and palms, can be a sign of anaemia.
Poor appetite: iron deficiency can reduce appetite, which in turn reduces iron intake further, creating a difficult cycle.
Frequent infections: a toddler who seems to catch every cold going may be showing signs of a weakened immune system.
Irritability: changes in mood and increased fussiness are sometimes linked to low iron.
Slow weight gain or growth: in more severe cases, iron deficiency can affect growth.

It is important to note that these signs can have many causes and are not specific to iron deficiency. If you are concerned, the right step is to speak to your health visitor or GP, who can arrange a blood test to check haemoglobin and ferritin (iron store) levels.

Iron-rich foods for babies and toddlers

The best way to prevent iron deficiency is through a varied diet that includes good sources of iron at each stage of feeding.

Haem iron: the most absorbable form

Iron comes in two forms. Haem iron, found in animal products, is absorbed by the body much more efficiently than non-haem iron. The best sources of haem iron for babies and toddlers include:

Red meat such as beef, lamb and pork
Poultry such as chicken and turkey (dark meat is higher in iron than white meat)
Fish, including tuna and sardines
Eggs (iron is mostly in the yolk)

Non-haem iron: plant-based sources

Non-haem iron is less well absorbed but still contributes meaningfully to iron intake, especially if consumed regularly and paired with vitamin C. Good plant-based sources include:

Lentils, chickpeas, kidney beans and other pulses
Tofu and tempeh
Dark green leafy vegetables such as spinach and kale
Fortified breakfast cereals (check the label for iron content)
Dried fruit such as apricots, figs and prunes (note these are also high in sugar, so offer in small amounts)
Wholemeal bread and some nuts and seeds (ground or as smooth nut butter to reduce choking risk)

The vitamin C boost

Vitamin C significantly enhances the absorption of non-haem iron when eaten at the same meal. Offering a source of vitamin C alongside plant-based iron is a simple and effective strategy. Good vitamin C sources to pair with iron-rich foods include tomatoes, peppers, broccoli, citrus fruit and kiwi.

Foods that reduce iron absorption

Some foods and drinks can reduce iron absorption when consumed at the same time. Tannins in tea and coffee, calcium in dairy products, and phytates in some wholegrains can all inhibit iron absorption. This is a reason to avoid giving babies and toddlers tea or coffee entirely, and to avoid giving large amounts of milk alongside iron-rich meals.

Frequently asked questions

What are the signs of iron deficiency in a baby?

Signs that may suggest iron deficiency include unusual tiredness or low energy, pale skin, poor appetite, slow weight gain, and increased susceptibility to infections. Iron-deficiency anaemia can also affect development and learning. Many babies with low iron have no obvious signs, which is why a varied diet with good iron sources is important preventively.

When is a baby most at risk of iron deficiency?

Babies are born with iron stores that typically last around 6 months. After that, dietary iron becomes essential. Premature babies and babies of low birth weight have smaller iron stores and may need supplementation from an earlier stage. Toddlers who drink large amounts of cows milk (over 400ml a day) are also at higher risk because milk is low in iron and can reduce appetite for iron-rich foods.

Which foods are highest in iron for babies?

Red meat such as beef and lamb is one of the richest sources of haem iron, which the body absorbs most easily. Other good sources include chicken, fish, eggs, lentils, beans, chickpeas, tofu and fortified breakfast cereals. Dark green vegetables such as spinach and kale also contain iron, though in a form that is less well absorbed. Serving plant-based iron sources alongside vitamin C (tomatoes, peppers, citrus) improves absorption.

Should my baby have an iron supplement?

Most healthy full-term babies who are eating a varied diet do not need iron supplements. Premature babies are often prescribed iron drops from early in their lives. If you are concerned about your baby's iron intake, speak to your health visitor or GP before starting any supplement: too much iron is harmful, and supplementation should only be used when indicated by a healthcare professional.

Can too much cows milk cause iron deficiency?

Yes. Cows milk is low in iron and can also reduce the absorption of iron from other foods. Toddlers who drink more than around 400ml of cows milk per day are at higher risk of iron deficiency because milk fills their appetite without providing much iron. The NHS advises limiting milk as a drink to around 300 to 400ml per day from 12 months and prioritising solid food for nutrition.

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