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As a sleep coach, I often see clients only after they have tried everything under the sun with no luck. Because I specialize in kiddos with harder problems, I also have seen a surprising number of clients with really severe issues that just didn’t sound like simple behavior.
One client had a toddler who was awake every night for hours and only wanted mom to stand up and hold him with his legs dangling down. Every time she tried to lay him down, he screamed.
Another client had a three-year-old who was bouncing off the walls at bedtime (a little normal), but then was also awake from 2-5 a.m. every night and nothing worked to get him back to sleep.
Another client had to put their toddler in the car every time they woke at night to get them back to sleep.
These are not “normal” behavioral issues. Something else is going on here. ferritin and sleep in children
Important caveat: I am not a doctor. I was trained in this topic by a pediatric sleep doctor 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.
Low ferritin and sleep problems in young children
Ferritin refers to the iron storage capacity in the blood. This is different from the amount of iron in the blood. Individuals can have enough iron, but if it’s not absorbed or stored, the body isn’t as able to utilize it. Babies get a big dose of ferritin at birth that wanes over teh first six months. Exclusively breastfed babies are supposed to receive iron supplementation by four- or six months. Some infants start out with lower levels of ferritin. Maternal low iron during pregnancy, silent reflux, or other factors can alter how much ferritin a child has. Over time, levels tend to drop.
Iron levels are usually tested by pediatricians at 9- or 12 months. However, this test is not an adequate indicator of ferritin levels. Iron levels can be normal, even when ferritin is really low.
Low ferritin alters the very structure or architecture of sleep in the brain. It is also related to significant bedtime and/or middle of the night discomfort that resembles Restless Legs Syndrome. Older children with RLS will tell you that their legs feel “twitchy” or “jumpy” or they "feel nervous" and they can’t get comfortable. Dr. Lewis Kass, pediatric sleep doctor, suggests that much of what we used to call “growing pains” is now thought to be a possible symptom of low ferritin.
Behaviors that stem from RLS can masquerade as garden variety bedtime protests. We think a child just can’t settle or is bouncing off walls to stall, but in fact, they are really and truly desperately uncomfortable.
I can tell you that all three of those clients from above came back with very low ferritin levels and once the levels started to rise, sleep problems virtually disappeared.
Symptoms
Low ferritin can occur in even 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 currently RLS is primarily diagnosed in older children, research has shown that in most of those cases, symptoms began in infancy and toddlerhood.
[Older children] They will say their legs feel “jumpy” “tickly” “prickly” or that they hurt. (They may say they feel "nervous" or "scared")
They take a long time (more than an hour) to go to sleep at bedtime. They want to be rocked, then not rocked. They want covers, then no covers. It seems like they just can’t get comfortable.
Kicking, thrashing, wanting legs up on something to sleep.
Lots of movement even when they're asleep. (Parents who resort to cosleeping will report that the child needs to sleep ON them or that there's so much movement that they have bruises or can't sleep because their child is moving so much.)
There is a long wakeup (an hour or more) in the middle of the night. It will also seem like nothing works reliably to get them back down.
A wide variety of behavioral 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 nursing, etc. (i.e., baby screams if nursing stops or parent tries to move away)
Risk factors
Mom had low iron in pregnancy
There was early cord clamping at birth (babies get a dose of ferritin at birth)
Family history of low iron/ferritin or Restless Legs Syndrome (I talked to one dad who didn't realize he had RLS until we started talking about it.
Child has (or had) silent reflux, eczema, or food intolerance (cow's milk, soy, etc.). These can cause gut inflammation that hinders iron absorption.
[Older children] Diagnosed or suspected ADHD. It's estimated that 50-75% of children with ADHD (and autism) have low ferritin levels.
Testing: Ferritin can be tested with a simple blood draw (I know, I know. That’s actually not that simple.) Results should come back quickly. Pediatricians' usual lower threshold for “normal” ferritin (<7µg) is considered too low when it comes to sleep. Sleep doctors generally want the score to be above 50µg. If your child is having significant sleep issues and the score comes back and the the pediatrician says it's “normal,” get the actual number and then consult a pediatric sleep doctor to be sure.
Here's another wrinkle. Pediatricians will often suggest testing hemoglobin (which is just a usual finger stick to test). If hemoglobin is low, chances are ferritin is too...but hemoglobin can be fine even though ferritin is low. A regular, standard iron test won't tell you what you need to know. Also, be sure that they actually test ferritin. I've seen parents get a whole blood panel done and ferritin wasn't tested.
Treatment: Treatment for low ferritin is prescription-level iron supplementation (i.e., multivitamins with iron or iron-rich foods won’t usually cut it.) Doctors typically need to oversee the dosage, etc. because incorrect iron dosing can be dangerous.
Ferritin levels unfortunately may take months to come up to the higher threshold, however, you should see improvement in sleep behaviors within a few weeks. In the meantime, stretching or leg massages can work at bedtime. Mild heat can also help symptoms. 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.
If you feel like your child’s sleep behavior is more extreme than just a behavioral issue, get their ferritin checked.
References
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
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.
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
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
Macall Gordon, M.A. has a B.S. from Stanford in Human Biology and an M.A. from Antioch University, Seattle in Applied Psychology, where she is currently a Sr. Lecturer. 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 (Little Livewires LLC). She comes to this work because she had two sensitive, intense children and she didn’t sleep for 18 years.