Symptoms of Iron Deficiency Anemia in Children

pregnant mother and young boy preparing fruit for a smoothie

By Rhianna Ross, RHN

Iron deficiency is the most common nutrient deficiency worldwide.

Symptoms of iron deficiency and their severity can vary from child to child; some children may only have one to two symptoms or even be symptom-free (also called asymptomatic).

Some of the symptoms listed below can also be caused by other nutrient deficiencies or underlying health issues. If your child’s iron levels have been tested and are optimal, you will need to explore other possibilities. Work with your health care practitioner to investigate.

Remember that your child’s health will be impacted long before iron deficiency anemia is diagnosed.

But iron needs don’t end with childhood. Iron is important for optimal health at every age. Iron deficiency can negatively impact both our physical and mental health.

Symptoms Related to Brain Formation and Function

normal blood graphic showing many red blood cells, next to anemic blood graphic showing fewer red blood cells
Iron is needed for the healthy development of brain structures. Iron is involved in the development of the brain and is needed to maintain proper function throughout life. Deficiencies can hinder development and harm brain function. This can cause a variety of issues such as poor cognition and poor sleep.

“Cognition is defined as ‘the mental action or process of acquiring knowledge and understanding through thought, experience, and the senses.’… It is in essence, the ability to perceive and react, process and understand, store and retrieve information, make decisions and produce appropriate responses.”

Cognition has a physical basis in the brain with over 100 billion nerve cells in a healthy human brain. Each of these can have up to 10,000 connections with other nerve cells called neurons.”

Mood & Behaviour Problems

Processing emotions, regulating behaviour, and mood are all parts of cognition. Iron deficiency anemia during development may alter cognition. If a child is suffering an iron deficiency when the brain is developing, lasting abnormalities in the brain may occur if iron stores are not replenished quickly. This can cause mood and behavioural issues.

Iron deficiency anemia in children can show up as the following:

  • Hyperactivity followed by exhaustion
  • Frequent tantrums and meltdowns
  • Hard time falling asleep, unhappy upon waking
  • Anxiety


Difficulty Learning

Difficulty concentrating, learning, and problem solving are all symptoms of iron deficiency. A deficiency of iron during periods of growth can cause lasting abnormalities in these areas of brain function.

  • Poor grades, difficulty learning
  • Difficulty paying attention or performing in school
  • Difficulty problem solving
  • Poor memory


symptoms of anemia include poor immunity, tantrums, eating ice or dirt, slow growth, dark under eye circles, learning difficulties; does your child have low iron

Poor Motor Skills

Children with iron deficiency often have delays in learning and performing new tasks like walking and crawling. The relationship between iron status in children and motor skills has been well studied and is connected to impaired myelination during early brain development. Myelination is the formation of a coating of fats and proteins, known as myelin, around nerve cells and neurons. Early supplementation in young babies is key to ensure proper myelination occurs.

Did You Know?

Symptoms of iron deficiency and their severity can vary; some children may have only one to two symptoms or even be asymptomatic.

Physical Symptoms of Iron Deficiency

Sleep Problems & Tiredness

Sleep problems, like difficulty falling or staying asleep, and feeling tired are associated with iron deficiency or anemia. If your child has sleep issues, get their iron tested. ⁠

Restless Legs

Tingling sensations and/or an uncontrollable urge to move the legs are symptoms of restless leg syndrome. This is an annoying health problem that is caused by iron deficiency or iron deficiency anemia. Iron is needed to make dopamine, an important neurotransmitter involved in muscle movement and emotional status.

Reduced Immunity

Low iron causes a weak immune system which results in more colds, fevers, and flu. Certain cells that are a part of our immune system need iron for metabolism and if iron is low, they will not create enough energy to work properly. Healthy iron levels in the body are needed for a strong immune system.⁠

Craving Ice, Dirt, or Clay (Pica)

Craving ice, dirt, or clay are common symptoms of low iron, zinc, and magnesium, especially in children. While the reasons aren’t totally clear, dirt and clay are likely a source of minerals.⁠

Stunted Growth & Development

Being shorter or smaller than other children of the same age group is a symptom of iron deficiency. Growing kids need iron. Without optimal levels, growth and development can be stunted. ⁠

Muscle Weakness & Low Stamina

Muscle weakness and reduced stamina are more common in children with iron deficiency than children with optimal iron levels. This is because iron is needed to deliver enough oxygen or energy. ⁠

Cold Hands & Feet

Cold hands and feet, a sign of poor circulation, are also a symptom of iron deficiency and anemia. Low iron causes less oxygen to be carried to the cells, tissues, and organs of the body, leading to poor circulation.⁠

Dizziness, Fast Heartbeat, Rapid Breathing

Dizziness, rapid or irregular heart rate, or feeling out of breath are signs of iron deficiency or anemia. When your iron is low, hemoglobin can’t carry adequate oxygen on your red blood cells to provide enough oxygen to your brain and heart. Hemoglobin is an iron-containing protein found in red blood cells that carry oxygen from our lungs to the rest of the body.

Iron deficiency can also cause hemoglobin levels to drop. When hemoglobin levels drop due to low iron, less oxygen makes it to our cells. To compensate, breathing rate may increase and cause shortness of breath.

This is also why heart palpitations can occur. Our heart works harder trying to move blood around the body faster to provide cells with more oxygen.

When to Supplement?

Early correction of iron deficiency and iron deficiency is important to protect children from lasting effects on development and growth.

While many doctors may say that someone is “in normal range” until your child becomes anemic, research shows that a deficiency in iron can start to harm them well before hemoglobin drops low enough to be diagnosed as anemic.

“While ID [iron deficiency] was presumed to cause most of its effects only if anemia was present, it is clear that many organs show morphologic, physiologic, and biochemical changes before there is any significant drop in hemoglobin concentration.” –

“Brain ID occurs before IDA [iron deficiency anemia]. It can alter the development of oligodendrocytes and result in hypomyelination of white matter, which is related to changes in startle response, auditory evoked potentials, and motor function in the infant (Beard, 2007; Todorich et al., 2009). Early ID also neurochemically alters the function of neurotransmitters. Animal models have shown that ID can alter the function of the frontal cortex, midline thalamus, and other brain regions by modifying the dopaminergic neurotransmission system (Beard and Connor, 2003).”

If you suspect your child or you may have low iron levels, based on risk factors or symptoms, a supplement can help. Having iron levels tested is recommended as a daily maintenance dose of iron will not be enough to correct low levels. If you or any family members have been diagnosed with hemochromatosis or another blood disease that affects iron regulation in the body, make sure to speak to a doctor to see if your child is also a carrier.

Diet can also help to support and increase iron levels. Read more about iron and food here.


KidStar® BioFe® Iron

KidStar® BioFe® is gentle and will not upset sensitive stomachs or stain teeth like common iron supplements. BioFe+ Iron Liquid is safe for the whole family, from infancy to adulthood.

The iron in BioFe is micronized and microencapsulated, protecting you from the side effects of iron, like constipation, black stools, tummy upset, and grey teeth. Microencapsulation also allows BioFe iron to be taken at the same time as foods and nutrients containing calcium.

Like all KidStar nutrients, our iron supplements do not contain sugar, artificial colours, artificial sweeteners and artificial flavours, soy, gluten and GMOs. KidStar BioFe Iron is available in a tasty liquid, unflavoured liquid drops and a tiny chewable tablet.

Find iron products here


Gentle, unflavoured, pure iron drops in an MCT base.

BioFe® Pure Iron Drops


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Iron for the Family Bundle

Iron for the Family Bundle


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Gentle, delicious, iron liquid formula for toddlers, children, and older.

BioFe+® Iron Liquid


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cartoon image of Rhianna Ross

About the Author

Rhianna Ross, R.H.N., is a registered holistic nutritionist based in Vancouver, BC. Rhianna has more than a decade of experience in the natural health and wellness industry, and currently works at KidStar Nutrients, where she enjoys reviewing and analyzing the latest nutritional research papers, meta-analyses, and journal articles.