Low ferritin: The little-known reason for chronic sleep issues in young children

Macall Gordon, M.A.
4 days ago
12 min read

Important caveat before I start: I am not a doctor. I was trained in this topic by a pediatric sleep doctor/pulmonologist and have read the research, but this is not medical advice and is not meant to diagnose a condition. Please consult with your medical provider or a local pediatric sleep clinic for any concerns about low ferritin and sleep.

As a sleep coach who specializes in hard problems, I often see clients only after they have tried everything under the sun and are still struggling. However, in the past five years or so, I have seen a surprising number with sleep problems so much worse than behavior (or even temperament) could explain.

One client had a toddler who required mom to stand up and hold him with his legs dangling down from 12-5 a.m. every night. Every time she even tried to sit down, he screamed.
Another client had a three-year-old who was bouncing off the walls at bedtime (would not lie down), taking over an hour to go to sleep, and was also awake from 2-5 a.m. every night. When they finally would cosleep, the parents reported being pummeled by repeated kicks while he was still asleep.
Another client said that the only way they could get their preschooler back to sleep after each of his many wakeups was to put them in the car and drive around.

All of them had tried sleep training, but the problem did not budge and worsened over time.

Nearly all the hardest problems I have seen across the thousands of families I have encountered had one thing in common: low ferritin.

ritin and sleep in children

Woman holding "HELP" sign, surrounded by children and a dog, indoors. She appears overwhelmed. Bright setting with soft colors.

The link between low ferritin and sleep

The culprit in each of these cases was low ferritin, which can result in pediatric Restless Legs Syndrome. The “restless” in RLS doesn’t mean that the legs twitch. It refers to the fact that movement helps dispel the twitchy discomfort that RLS causes.

Currently, diagnostic criteria prevent assessment of RLS in children younger than six or eight years. Criteria require a child to be able to verbalize that their legs hurt. Young children may not know that the sensations are coming from their body. It also does not always manifest as pain. Little ones may feel “on edge” or “scared,” but these are interpretations of the sensations in their bodies. They’re just too young to identify that. RLS is happening in younger children; practitioners just aren’t looking for it.

The other issue is that practitioners are looking for “iron deficiency” which is a ferritin level of 7 or below. RLS and other sleep disruptions can occur at levels above this. Even that level of 7 is considered absurdly low by some (Abdullah et al., 2017; Mukhtarova et al., 2022). A recent paper in The Lancet: Hematology recommends a ferritin cutoff of 20 (Mei et al., 2021). Some researchers are alarmed that potentially iron-deficient younger children are being missed for sometimes years at a time (Al-Shawwa et al., 2022; Leung et al., 2020; Mukhtarova et al., 2022; Tilma et al., 2013).

What is ferritin?

Ferritin is a protein that stores iron in cells so that there’s not too much of it floating in the bloodstream. Ferritin releases iron as it’s needed. Ferritin is different from the amount of iron contained in the red blood cells (hemoglobin).

Individuals can have enough iron in their blood, but if it’s not absorbed or stored in ferritin, the body cannot use it.

Babies receive both iron and ferritin in utero, as well as at birth while the umbilical cord is pulsing (Andersson et al., 2011). These stores of iron gradually decrease over the first four to six months. Exclusively breastfed babies are supposed to receive iron supplementation.

Ferritin is critical for brain functioning, memory, and nervous system development, especially in the first few years (Georgieff, 2017).

Symptoms of low ferritin

Low ferritin can occur in even infants and very young children. We are more familiar with the symptoms of older children because they can tell us what’s bothering them. In infants and toddlers, we only have behaviors to go on. While RLS is primarily diagnosed in older children, research has shown that in most of those cases, symptoms began in infancy and toddlerhood (Muhle et al., 2008; Picchietti & Stevens, 2008).

Low ferritin is tricky to detect in younger children because it can masquerade as garden-variety bedtime protest or shenanigans.

Low ferritin can masquerade as garden-variety bedtime protest or shenanigans.

A child who can’t settle or is bouncing off walls may appear to be stalling, but in fact, they are really and truly uncomfortable. In my experience, about 90% of the worst, hardest sleep problems I have encountered have been due to low ferritin (confirmed by blood test).

Symptoms:

Sudden onset. The child was sleeping pretty well and then it went sideways, getting worse over time.
Child takes a long time (1 hour+) to fall asleep at bedtime. They want to be rocked, then not rocked. They want covers, then no covers. They refuse to lie down. They just can’t get comfortable.
Younger children (infants) scream to be picked up off the mattress. When holding or sitting, they need to have their legs dangling (i.e., no pressure on them.)
At bedtime, lots of kicking, standing, wanting legs up on something (the wall, the side of the crib, you) to sleep.
Lots of movement even when they’re asleep. (Parents who resort to cosleeping will report so much movement that they can’t sleep.)
When cosleeping, they need to sleep on top of you or they need to be incredibly (too) close, often needing to touch you all night.
There is a long wakeup (1+ hours) in the middle of the night. It will also seem like nothing works reliably to get them back down.
Older children will say their legs feel “jumpy,” “tickly,” “prickly,” or that their legs, knees, feet hurt (growing pains are now thought to be RLS).
They may say they feel “nervous,” “scared,” or that they just “can’t sleep.”
Solid attempts at behavioral (sleep training) strategies haven’t worked...at all.
The child wakes at night moaning, screaming, or crying, or they do this in their sleep.
For infants, extreme difficulty with anything but full body contact, constant latch/nursing, etc. (i.e., baby screams if nursing stops or parent tries to move away), kicking/thumping legs (Bruni et al., 2015)
Breath-holding spells (Hamed et al., 2018)

Risk factors

Mom had low iron, low ferritin, or Restless Legs Syndrome in pregnancy (about 20% of moms have RLS in pregnancy)
No delay of umbilical cord clamping at birth (Ceriani Cernadas et al., 2010). Early cord clamping doubles the risk of low ferritin (Andersson et al., 2011; Ceriani Cernadas et al., 2010; McDonald et al., 2013)
Prematurity or intrauterine growth restriction
Family history of low iron/ferritin, growing pains, or Restless Legs Syndrome (Tilma et al., 2013). (In one study, 87% of the children with RLS had a parent with RLS; Muhle et al., 2008)
Child has (or had) silent reflux, eczema, or food intolerance (cow’s milk, soy, etc.). These can cause gut inflammation that hinders iron absorption (Lee, 2024; Pfeiffer & Looker, 2017).
Older children with a diagnosis of ADHD or ASD or suspected symptoms. It’s estimated that 50-75% of children with ADHD/ASD have low ferritin levels (Dosman et al., 2007; Kanofal et al., 2007; Kanofal et al., 2004; Wang et al., 2017).
Lead exposure in the home

Testing

Pediatricians will often suggest testing iron levels (which is just a standard fingerstick). If iron is low, chances are that ferritin is too, but iron can be normal even when ferritin is low. The body technically depletes ferritin first, then it starts working through iron. Some researchers contend that low iron (anemia) is a late-stage indicator of iron deficiency and that we should test for ferritin more routinely and earlier (Georgieff, 2017).

Ferritin testing unfortunately requires a blood draw (I know, I know. Yikes.) Results should come back quickly. Here’s another wrinkle: You can’t settle for the office telling you that ferritin is “normal.” Pediatricians’ usual threshold for “normal” ferritin (<7µg). Remember, they are only worried about “iron deficiency.” In the presence of sleep problems, sleep doctors generally want ferritin levels to be 50 µg or higher (Allen et al., 2018). If your child is experiencing significant sleep issues and the pediatrician says it's “normal,” get the actual number and then consult a pediatric sleep specialist for assessment and treatment.

If your child has significant sleep issues and the pediatrician says it's “normal,” get the actual number.

Also, be sure that they test ferritin. I’ve seen parents get a whole blood panel done and ferritin wasn’t tested..

Treatment

Treatment for low ferritin typically involves prescription-level iron supplementation. Multivitamins with iron, over-the-counter iron supplements, or iron-rich foods will not raise levels. Doctors typically need to prescribe and oversee the dosage because incorrect iron dosing can be dangerous. (Important note: DO NOT supplement with more than the label amount of iron on your own.)

The other hard fact is that ferritin levels may take several months to reach the target. However, you should see improvement in sleep behaviors before then. Most sleep doctors also want to monitor progress over time to be sure that supplementation is working.

What can you do in the meantime? While you wait for iron supplementation to kick in, stretching or leg massages can help at bedtime. Magnesium lotion on the child’s feed and Epsom salts in their bath can also really help. You can also give a young one a bolster or pillow to prop their legs up on.

The good news is that once levels start to rise, you should see massive differences. The toddler in my client examples went from needing to be put in the car to go back to sleep to walking to his bed, getting in, and sleeping through the night.

The toddler who needed to be put in the car to go back to sleep started walking to his bed, getting in, and sleeping through the night once his levels normalized.

If you feel like your child’s sleep behavior is more extreme than just a behavioral issue, get their ferritin checked.

Do you have more questions or need to discuss your situation? I offer a 30-minute Zoom call to discuss low ferritin and see if it might be your culprit. Book a low-ferritin call.

Have you been through the low ferritin journey? Willing to share some of this information? I’m collecting some anecdotal data to share with researchers to raise awareness. Fill out my short survey here.

Frequently Asked Questions about Low Ferritin

Do I need a sleep study to test this?

Not necessarily, although children who have sleep apnea (snoring, mouth breathing) often have comorbid low ferritin. A sleep study will only measure movement during sleep. They diagnose Restless Sleep Disorder, which can be different. If your child does not snore or mouth-breathes during sleep, a blood test is the quickest way to check for low ferritin. You do not need a sleep study for that.

Can a baby have low ferritin?

The iron and ferritin that babies get before and during birth should sustain them for at least the first four to six months. Plus, trying to get the okay for a blood draw on an infant isn’t easy. However, it does happen that some infants are low on ferritin. I had one client with an 8-month-old who tested with a ferritin of 1. I usually only recommend testing infants when we have totally ruled out every other possibility, and sleep is just truly awful. In this case, I honestly recommend booking a call with me to help you figure this out.

Can I just offer a multivitamin or iron drops myself?

If ferritin is truly low, an over-the-counter dose won’t hurt, but it also won’t bring levels up. You could waste precious time. Ferritin plays a crucial role in nervous system development. Plus, the fractured and disrupted sleep that’s happening isn’t great for your child (or your family). I usually tell parents to start an over-the-counter supplement while they’re waiting to get a test or prescription. DO NOT give your child more than the recommended dose of iron without a doctor's prescription.

I’ve heard that oral iron doesn’t always work. What then?

This is true. If a child has significant gut inflammation or other metabolic issues, they may not absorb oral iron well and may actually require iron transfusions. I believe this is rare, but it does happen. This is why parents need to get a test to see how low ferritin is, and then they need to get seen by a pediatric sleep doctor or other specialist so that levels are monitored over time.

References

Abdullah, K., Birken, C. S., Maguire, J. L., Fehlings, D., Hanley, A. J., Thorpe, K. E., & Parkin, P. C. (2017). Re-evaluation of serum ferritin cut-off values for the diagnosis of iron deficiency in children aged 12-36 months. The Journal of Pediatrics, 188, 287–290. https://doi.org/10.1016/j.jpeds.2017.03.028

Allen, R. P., Picchietti, D. L., Auerbach, M., Cho, Y. W., Connor, J. R., Earley, C. J., Garcia-Borreguero, D., Kotagal, S., Manconi, M., Ondo, W., Ulfberg, J., Winkelman, J. W., & International Restless Legs Syndrome Study Group (IRLSSG). (2018). Evidence-based and consensus clinical practice guidelines for the iron treatment of restless legs syndrome/Willis-Ekbom disease in adults and children: An IRLSSG task force report. Sleep Medicine, 41, 27–44. https://doi.org/10.1016/j.sleep.2017.11.1126

Al-Shawwa, B., Sharma, M., & Ingram, D. G. (2022). Terrible twos: Intravenous iron ameliorates a toddler’s iron deficiency and sleep disturbance. Journal of Clinical Sleep Medicine, 18(2), 677–680.

Andersson, O., Hellström-Westas, L., Andersson, D., & Domellöf, M. (2011). Effect of delayed versus early umbilical cord clamping on neonatal outcomes and iron status at 4 months: A randomised controlled trial. BMJ (Clinical Research Ed.), 343, d7157. https://doi.org/10.1136/bmj.d7157

Bruni, O., Angriman, M., Luchetti, A., & Ferri, R. (2015). Leg kicking and rubbing as a highly suggestive sign of pediatric restless legs syndrome. Sleep Medicine, 16(12), 1576–1577. https://doi.org/10.1016/j.sleep.2015.07.016

Ceriani Cernadas, J. M., Carroli, G., Pellegrini, L., Ferreira, M., Ricci, C., Casas, O., Lardizabal, J., & Morasso, M. D. C. (2010). [The effect of early and delayed umbilical cord clamping on ferritin levels in term infants at six months of life: A randomized, controlled trial]. Archivos Argentinos de Pediatria, 108(3), 201–208.

Dosman, C., Witmans, M., & Zwaigenbaum, L. (2012). Iron’s role in paediatric restless legs syndrome: A review. Paediatrics & Child Health, 17(4), 193–197. https://doi.org/10.1093/pch/17.4.193

Georgieff, M. K. (2017). Iron assessment to protect the developing brain. The American Journal of Clinical Nutrition, 106(Suppl 6), 1588S-1593S. https://doi.org/10.3945/ajcn.117.155846

Hamed, S. A., Gad, E. F., & Sherif, T. K. (2018). Iron deficiency and cyanotic breath-holding spells: The effectiveness of iron therapy. Pediatric Hematology and Oncology, 35(3), 186–195. https://doi.org/10.1080/08880018.2018.1491659

Konofal, E., Cortese, S., Marchand, M., Mouren, M.-C., Arnulf, I., & Lecendreux, M. (2007). Impact of restless legs syndrome and iron deficiency on attention-deficit/hyperactivity disorder in children. Sleep Medicine, 8(7–8), 711–715.

Konofal, E., Lecendreux, M., Arnulf, I., & Mouren, M. C. (2004). Iron deficiency in children with attention-deficit/hyperactivity disorder. Archives of Pediatrics & Adolescent Medicine, 158(12), 1113-1115.

Lee, N. H. (2024). Iron deficiency in children with a focus on inflammatory conditions. Clinical and Experimental Pediatrics, 67(6), 283–293.

Leung, W., Singh, I., McWilliams, S., Stockler, S., & Ipsiroglu, O. S. (2020). Iron deficiency and sleep - A scoping review. Sleep Medicine Reviews, 51, 101274.

McDonald, S. J., Middleton, P., Dowswell, T., & Morris, P. S. (2013). Effect of timing of umbilical cord clamping of term infants on maternal and neonatal outcomes. Cochrane Database of Systematic Reviews, 2013(7), CD004074. https://doi.org/10.1002/14651858.CD004074.pub3

Mei, Z., Addo, O. Y., Jefferds, M. E., Sharma, A. J., Flores-Ayala, R. C., & Brittenham, G. M. (2021). Physiologically based serum ferritin thresholds for iron deficiency in children and non-pregnant women: a US National Health and Nutrition Examination Surveys (NHANES) serial cross-sectional study. The Lancet. Haematology, 8(8), e572–e582. https://doi.org/10.1016/S2352-3026(21)00168-X

Muhle, H., Neumann, A., Lohmann-Hedrich, K., Lohnau, T., Lu, Y., Winkler, S., Waltz, S., Fischenbeck, A., Kramer, P. L., Klein, C., & Stephani, U. (2008). Childhood-onset restless legs syndrome: Clinical and genetic features of 22 families. Movement Disorders, 23(8), 1113–1121

Mukhtarova, N., Ha, B., Diamond, C. A., Plumb, A. J., & Kling, P. J. (2022). Serum ferritin threshold for iron deficiency screening in one-year-old children. The Journal of Pediatrics, 245, 217–221. https://doi.org/10.1016/j.jpeds.2022.01.050

Peirano, P. D., Algarín, C. R., Chamorro, R. A., Reyes, S. C., Durán, S. A., Garrido, M. I., & Lozoff, B. (2010). Sleep alterations and iron deficiency anemia in infancy. Sleep Medicine, 11(7), 637–642. https://doi.org/10.1016/j.sleep.2010.03.014

Pfeiffer, C. M., Sternberg, M. R., Schleicher, R. L., Haynes, B. M. H., Rybak, M. E., & Pirkle, J. L. (2013). The CDC’s Second National Report on Biochemical Indicators of Diet and Nutrition in the U.S. Population is a valuable tool for researchers and policy makers. The Journal of Nutrition, 143(6), 938S-47S. https://doi.org/10.3945/jn.112.172858

Picchietti, D. L., & Stevens, H. E. (2008). Early manifestations of restless legs syndrome in childhood and adolescence. Sleep Medicine, 9(7), 770–781. https://doi.org/10.1016/j.sleep.2007.08.012

Tilma, J., Tilma, K., Norregaard, O., & Ostergaard, J. R. (2013). Early childhood-onset restless legs syndrome: Symptoms and effect of oral iron treatment. Acta Paediatrica, 102(5), e221-6.

Wang, Y., Huang, L., Zhang, L., Qu, Y., & Mu, D. (2017). Iron Status in Attention-Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysis. Plos One, 12(1), e0169145. https://doi.org/10.1371/journal.pone.0169145

About Macall Gordon

Macall Gordon, M.A. has a B.S. from Stanford in Human Biology and an M.A. from Antioch University, Seattle in applied psychology. She is clearly a research nerd. She researches and writes about temperament, sleep, and the gap between research and advice. She is also a certified pediatric sleep consultant working with parents of alert, non-sleeping children. She comes to this work because she had two sensitive, intense children, and she didn’t sleep for 18 years.