Iron deficiency is one of the most common nutritional deficiencies globally, affecting around 2 billion people. It is especially prevalent among women of childbearing age, children, and those following restrictive diets. Iron is an essential mineral that has several important functions in the body. It is a key component of hemoglobin, the protein that carries oxygen in the blood. Iron is also involved in energy production, immune function, brain development, and more. When iron levels are low, it can impair these critical processes and lead to anemia and other problems. But can insufficient iron also affect behavior and brain function? Here is an overview of the evidence surrounding how low iron levels may impact behavior, cognition, and mental health.
Iron’s Role in The Brain
Although iron is found throughout the body, it is particularly vital within the brain. The brain demands around 20% of the body’s iron stores. Iron helps with the development of the hippocampus, basal ganglia, and dopamine neurotransmitter systems during infancy and childhood. These are brain regions and networks crucial for cognition, memory, and emotion regulation. Throughout life, iron continues playing an essential role in neurological function by:
- Synthesizing neurotransmitters like dopamine, norepinephrine, and serotonin
- Myelinating nerve fibers to allow neurons to properly conduct signals
- Providing oxygen to brain tissue
- Regulating synaptic plasticity which enables learning and memory
Given iron’s critical tasks within the brain, it is not surprising that iron deficiency can lead to central nervous system impairments. Even moderate iron deficiency without anemia can negatively impact proper brain functioning and behavior if prolonged.
Research indicates that low iron levels can detrimentally affect cognitive skills and academic performance, especially in infants and children. Impacts may include:
Infants and toddlers with iron deficiency tend to experience developmental delays, particularly in motor functioning and language skills. This may be due to iron’s role in myelination of nerve fibers during this rapid period of brain growth.
Impaired Learning & Memory
Iron deficiency hampers the brain’s ability to transmit and process information efficiently. This can lead to difficulties learning new information, retaining knowledge, and performing complex tasks. Studies of school-aged children with iron deficiency show disadvantages in areas like memory, verbal learning, and selective attention compared to peers with healthy iron levels.
Children with chronic, severe iron deficiency score lower on cognitive tests and have reduced IQ levels. This may persist even after treatment to restore iron levels. The hippocampus, important for learning and memory, appears especially vulnerable to low iron intake during early childhood.
Poor Academic Achievement
Given the detrimental effects low iron can have on cognitive skills, it is not surprising research consistently shows it also impairs academic achievement. Iron deficient children tend to lag behind peers in areas like reading scores, spelling, and mathematical reasoning.
|Study||Findings on Iron Deficiency and Cognition|
|Iron Status and Cognitive Performance in Women of Reproductive Age in Burkina Faso, Africa (2018)||Even mild iron deficiency was linked with poorer working memory, learning, and cognitive flexibility in women.|
|Iron Deficiency and Cognitive Functions in School Going Adolescent Females in Rural Area of Central India (2017)||Indian adolescent girls with iron deficiency showed impaired learning, memory, perception, and mathematical achievement.|
|Iron Deficiency Anemia in Early Childhood: Long-Lasting Effects on Auditory and Visual System Functioning (2016)||Chilean preschoolers with chronic iron deficiency performed worse on cognitive tests than peers, even after iron repletion therapy.|
The data indicates iron supplementation can often improve some aspects of cognition, especially when given early in childhood. However, certain effects may not fully resolve. This highlights the importance of adequate iron nutrition in expectant mothers, infants, and growing children when the brain is rapidly developing.
Psychological & Behavioral Impacts
In addition to hampering cognitive skills, iron deficiency may also contribute to psychological difficulties. Potential associations include:
Some research indicates iron deficiency can increase risks for depression. This may be due to altered dopamine function and reduced availability of iron for neurotransmitter synthesis. Depressive symptoms sometimes improve when iron levels are corrected.
Studies report links between low iron stores and elevated anxiety levels, likely due to impaired neurotransmitter activity. Animal studies also observed increased anxiety-like behaviors in iron deficient models.
Irritability & Lethargy
Children with severe or chronic iron deficiency often exhibit greater irritability. They may also demonstrate signs of apathy, reduced alertness, or lack of interest in their surroundings. Such symptoms usually improve after iron supplementation.
Some correlations have been observed between low iron and increased rates of ADHD. However, results are inconsistent. It is unclear if iron deficiency actually causes ADHD or is just associated with it in some cases. More research is needed in this area.
Infants with iron deficiency tend to be less engaged during interactions and make less eye contact. Toddlers may exhibit diminished interest in their surroundings and be slower to initiate play. These social effects are likely downstream results of cognitive delays and irritability.
Pica is a disorder involving cravings to eat non-food or non-nutritive items, like dirt, clay, or ice. It can sometimes result from iron deficiency, as it is the body’s attempt to obtain missing nutrients. Pica often resolves when iron levels are replenished.
|Study||Findings on Iron Status and Mental Health|
|Iron Deficiency Anemia and Behavioral Problems in Children (2012)||Toddlers in Turkey with iron deficiency anemia displayed more anxiety, depression, social problems, and aggressive behavior.|
|The Relationship between Iron Deficiency Anemia and Depression in Women of Reproductive Age (2018)||Women with iron deficiency in Iran were over 3 times more likely to experience clinical depression.|
|The Association between Iron Deficiency and ADHD in Children (2012)||No clear link found between iron deficiency and ADHD in Australian children.|
While associations exist between iron deficiency and various behavioral conditions, causation is not fully established in all cases. Randomized trials correcting iron levels and examining impacts on psychology over time are still needed.
How might insufficient iron produce cognitive and behavioral disturbances? Potential mechanisms include:
- Impaired Neurotransmitter Function – Iron is required to synthesize dopamine, norepinephrine, serotonin and other critical neurotransmitters in the brain.
- Altered Myelination – Iron enables myelination of nerve fibers so neurons can transmit signals properly. Disruption of myelination pathways likely contributes to cognitive impairments.
- Reduced Hippocampal Health – The hippocampus seems particularly vulnerable to low iron intake. Impacts on learning, memory, and mood regulation may stem largely from hippocampal damage.
- Hypoxia – With insufficient iron, hemoglobin levels fall reducing oxygen transport to the brain. Neural hypoxia can directly damage cognition and behavior.
- Impaired Synaptic Plasticity – Iron helps regulate plasticity and remodeling of synapses in response to stimuli. This process is integral to learning and development.
Overall, inadequate iron appears to disrupt both structural and functional neural pathways critical for cognitive skills and emotional processing. However, more research is needed to fully elucidate all mechanisms.
Restoring Iron Levels
The good news is that many behavioral effects of iron deficiency can be reversed if iron levels are restored, especially when caught early. Strategies to replenish iron stores include:
- Iron supplements – These are often used to quickly boost iron intakes, especially if deficiency is severe.
- Eating iron-rich foods – Great options include red meats, seafood, beans, lentils, spinach, and iron-fortified cereals.
- Treatment for underlying causes – Consider if heavy menstrual bleeding, gastrointestinal issues like celiac disease, or helicobacter pylori infection are causing iron malabsorption.
- Avoid excess coffee/tea with meals – Tannins can inhibit iron absorption from food.
- Enhance iron absorption – Eat foods rich in vitamin C and avoid calcium supplements with meals.
Ideally, replenishing iron through diet should be the long-term goal for milder deficiencies. Supplements are useful for quickly restoring iron levels but may cause constipation or stomach upset. Work with a healthcare provider to determine the best options.
In summary, iron deficiency appears capable of impairing cognitive skills, achievement, and behavior in developing children. It may also increase risks for certain psychological conditions across age groups, possibly by interfering with neurotransmitter synthesis and neuron functioning. However, more research is still needed on definitively proving causation in humans. Restoring healthy iron levels through diet and supplementation can often correct these disturbances, especially when addressed promptly. But if left uncorrected, iron deficiency can have lasting impacts on neurological development and mental health into adulthood. Maintaining adequate iron intake should therefore be a priority for at-risk groups like children and women of childbearing age.