During many of my consultation calls, I hear parents express their frustration about their children’s lack of sleep. Many are at their wit’s end, ready to give it one more try before resigning themselves to the idea that their kids are simply not good sleepers. In sleep training, we spend a lot of time focusing on the day-to-day activities of these children, aiming to establish structure and routine to help them sleep better at night. We typically start by examining bedtime routines, sleep environments, and daily schedules. However, an often-overlooked factor is the impact of nutrition, particularly iron levels, on sleep. Growing research highlights that iron deficiency anaemia (IDA) has a direct impact on sleep disruptions in infants and young children.
What is iron deficiency anaemia?
Iron deficiency anaemia occurs when the body lacks sufficient iron to produce healthy red blood cells, which are crucial for transporting oxygen throughout the body. Iron is a vital component in the production of red blood cells, and an inadequate supply can lead to anaemia.
As the most prevalent type of anaemia, iron deficiency anaemia arises when dietary iron intake is insufficient. While people often overlook nutritional deficiencies in infants and children, iron deficiency is actually the most widespread nutrient shortage across the globe, affecting an estimated 20-25% of infants.
Why is iron deficiency anaemia common among babies?
Although babies are born with some iron stored in their bodies, their rapid growth—encompassing brain development as well as physical and mental progress—demands a significant amount of iron. To support this developmental surge, infants require substantial iron absorption each day, which is why iron deficiency is prevalent, particularly between the ages of 9 and 24 months.
This deficiency poses a serious concern because infants with iron deficiency anaemia face not only physical health challenges but also sleep disturbances, potentially impacting their cognitive and behavioural development over the long term.
How does iron deficiency anaemia affect sleep?
This research paper sleep alterations and iron deficiency anemia in infancy mentions “we found that infants with IDA showed different motor activity patterning in all sleep-waking states and several differences in sleep states organization. Sleep alterations were still apparent years after correction of anemia with iron treatment in the absence of subsequent IDA. We suggest that altered sleep patterns may represent an underlying mechanism that interferes with optimal brain functioning during sleep and wakefulness in former IDA children.”
This study, conducted by the University of Chile and the University of Michigan, highlights the intricate relationship between iron levels and sleep, emphasising several key findings:
- Sleep Spindles: Studies have shown that infants with iron deficiency anaemia (IDA) exhibit changes in their sleep spindle activity. Sleep spindles, which are unique patterns of brainwaves that occur during non-REM sleep, are very important motor functions and memory consolidation. In infants affected by IDA, there is a noticeable reduction in the frequency and intensity of these spindles, pointing to potential challenges in brain development and the quality of sleep.
- Sleep/Wake Patterns: Infants suffering from iron deficiency anemia (IDA) typically display unique sleep and wake behaviors. They often have prolonged daytime naps, endure more disturbed sleep at night, and have reduced durations of deep, restorative non-REM sleep. This paper has stated “By using actigraphic recording data we found that 6-month-old IDA infants napped longer during the day and were more restless during sleep, with increased time awake and decreased time in QS at night. Furthermore, despite improvements in iron status after iron therapy, some differences in sleep patterns were still statistically significant”, indicating the importance of iron. Although treating the anaemia with iron supplementation can address some issues, certain differences in their sleep patterns may persist as they grow, suggesting enduring impacts on their sleep architecture.
- Persistent effects on childhood: Research shows that babies who had IDA during infancy, carried on having sleep problems throughout childhood. This papers found that 4 year old children who had IDA during infancy still have altered sleep organisation throughout the night.
- Differences in REM Sleep: This study, conducted on 4 year olds, demonstrates that IDA impacts both the timing and length of REM sleep episodes. Specifically, REM episodes tend to be longer earlier in the night and shorter later on, disrupting the natural flow of sleep cycles.
- First Sleep Cycle: The research also indicates that children with IDA experience shorter durations of deep sleep (SWS) and NREM2 stages during their initial sleep cycle, coupled with a reduced time taken to enter REM sleep. This pattern may suggest lasting effects on the brain’s ability to manage sleep efficiently.
Does this matter?
Yes, of course it does. These findings suggest that the lack of iron has a direct impact on the mental and physical development of babies and it also has a direct impact on their sleep quality. If the deficiency is strong enough, it can show up in the form of:
- Acting irritable
- Becoming extra fussy and having mood swings
- Noticeable changes in behaviour – learning and memory.
- Overly fatigue
Improving children’s iron level
- Formula fed and breast fed babies: If your baby is breastfed, pay attention to your own diet to ensure they’re receiving essential nutrients through your milk. For formula-fed infants, the formula already includes added iron.
- At 4 months: AAP recommends giving a daily iron supplement until they begin eating iron-rich foods.
- Iron-rich foods: Once food is introduced, make a conscious decision to include iron-rich food in the meals (spinach, lentils beans, lean meat and so forth). Pair with vitamin C-rich food for the optimal meal.
- Get advice: Pay attention to your child and if you do see any symptoms such as fatigue, fussy or pale skin, get in touch with your paediatrician. If diagnosed with IDA, talk with them to see how you can help your child and if iron supplements are needed. This advice will need to be doctor led.
In summary, closely monitoring your child’s health is crucial. Iron is essential for your child’s growth, development, and ability to sleep well. If you notice any symptoms of deficiency, have them evaluated immediately. Even if symptoms are not obvious and you’ve addressed all sleep-related factors but nights are still disturbed, it’s wise to conduct a thorough check-up. Ensuring everything is fine never hurts!
