There's no reliable evidence to suggest that iron supplements will help with your toddler's sleep

It's unlikely that your otherwise well toddler is waking a lot at night or having sleep problems because of low iron stores. It's been suggested that low iron stores cause what has been labelled as Restless Leg Syndrome or Periodic Limb Movements in early childhood. But advice to give your toddler iron supplementation for toddler sleep problems is not evidence-based.

The evidence that is used to suggest that iron supplements could help with a toddler's sleep is extremely weak, and doesn't take into account the effects on a toddler's night-time leg movements of

• Circadian or body clock disruption

• The dialling up effects of low sensory motor stimulation, such as lying awake on a mattress for long periods.

What does the science say about iron supplements and toddler sleep?

This theory that iron supplements might help is based upon single case studies or anecdotal evidence, in which authors have claimed that iron supplementation, whether oral or intravenous, improved children's restless leg movements over time. However, researchers also acknowledge that there is no data which shows what a normal or abnormal amount of leg movement might be for babies and toddlers in the night.

Unnecessary iron supplementation might result in tummy discomfort for your little one

The side-effects of giving your little one oral iron supplements can be constipation, dark stools, and tummy discomfort. Correction of true iron deficiency in older children is known to take weeks or months by oral supplementation. It's quite possible that a long and unnecessary course of iron supplementation could result in low-grade tummy discomfort for your toddler, affecting appetite. I recommend only using oral iron supplementation when your GP advises that this is truly necessary.

Doing a blood test can be very distressing for toddlers

Taking blood from your toddler to measure haemoglobin and iron (or ferritin) stores typically requires that your toddler is restrained, so toddlers often become very upset, struggling or screaming, when blood is taken. This is why blood tests are best avoided in toddlers unless your doctor advises it is important to proceed.

If your little one has not been having repeated viral or respiratory tract infections and is otherwise well and active, but you have sleep concerns, I recommend that you work through the steps of The Possums Sleep Program, without worrying about your toddler's iron or ferritin stores. If you still have concerns after a few weeks of trying the sleep program's strategies, please talk this over with your GP. It's very unlikely that iron stores have a role to play.

You can find out about iron rich foods for your little one here.

If your toddler has neurodevelopmental challenges, there may be a role for screening for iron deficiency. Please discuss this with your doctor.

Selected references

Al-Shawwa B, Sharma M, Ingram D. Terrible twos: intravenous iron ameliorates a toddler's iron deficiency and sleep disturbance. Journal of Clinical Sleep Medicine. 2022;18(2):677-679.

Kotagal S. Sleep-wake disorders of childhood. Continuum. 2017;23(4):1132-1150.

McWilliams S, Singh I, Leung W. Iron deficiency and common neurodevelopmental disorders - a scoping review. Plos One. 2022;17(9):e0273819 0273819.