Iron is an essential component of haemoglobin. Iron deficiency leads to anaemia (low haemoglobin concentration).
Iron deficiency causes microcytic hypochromic anaemia. Microcytic refers to small red blood cells with a low mean corpuscular volume (MCV). Hypochromic refers to pale cells due to a reduced haemoglobin concentration.
The groups at highest risk are:
- Premature and low birth weight infants
- Children aged 6–24 months
- Toddlers with selective eating
- Adolescents during growth spurts
- Adolescent girls due to menstruation
Causes
Several scenarios can lead to iron deficiency:
- Insufficient dietary iron (e.g., fussy toddlers)
- Excessive cow’s milk intake
- Increased iron requirements during rapid growth phases
- Reduced iron absorption (e.g., coeliac disease)
- Loss of iron through bleeding (e.g., menstruation in adolescent girls)
Dietary insufficiency is the most common cause in children. During growth, iron requirements often exceed the dietary intake.
Excessive cow’s milk intake can cause iron deficiency by several mechanisms:
- Low in iron
- Calcium and casein inhibit iron absorption
- It can cause microscopic intestinal bleeding in infants under 12 months
Signs and Symptoms
Key signs and symptoms that are specific to iron deficiency include:
- Pica (e.g., eating dirt, soil or ice)
- Brittle hair and nails
- Reduced growth
- Developmental and behavioural effects (e.g., irritability and poor concentration)
- Koilonychia (spoon-shaped nails)
- Angular cheilitis (inflammation at the corners of the mouth)
- Atrophic glossitis (a smooth tongue due to atrophy of the papillae)
Blood Results
Iron deficiency anaemia in children causes:
- Low haemoglobin
- Low mean corpuscular volume (MCV)
- Low mean corpuscular haemoglobin (MCH)
- Low ferritin (may be normal or raised with inflammation)
- Raised total iron-binding capacity (TIBC)
- Raised transferrin
- Low transferrin saturation
Management
Management involves treating the underlying cause and correcting the anaemia. In children, the underlying cause is usually dietary deficiency, so input from a dietician can be helpful. General advice includes:
- Increase dietary iron intake (e.g., meats and fortified foods)
- Having vitamin C with meals (vitamin C helps with iron absorption)
- Limiting cow’s milk intake in toddlers
Iron can be supplemented with ferrous sulfate or ferrous fumarate, which slowly corrects the iron deficiency. Oral iron causes constipation and black coloured stools.
Blood transfusions are very rarely necessary. Children are generally able to tolerate a low haemoglobin well and can be given time to correct the anaemia.
Last updated March 2026
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