How iron deficiency affects the body

The body needs nutrients like iron to function properly. Iron is considered an essential mineral because of its role. Thus, it is necessary to learn the effects of iron deficiency.

Plate containing iron-rich foods

Side effects of iron deficiency on the body include depression, paleness, strange cravings, unusual tiredness and even neurological problems like attention deficit hyperactivity disorder (ADHD).

Eating foods that contain iron such as dark leafy vegetables, whole-grain bread, fortified breakfast cereals, tofu, lentils, liver, and cashew. legumes, pumpkin seeds and iron supplements can help retain the body's iron store, preventing these side effects.

You may wonder why the body needs iron. Iron is very important to the body because the body needs it to produce haemoglobin, the protein in red blood cells that carries oxygen and gives blood its red colour. Aside from haemoglobin, iron is also found in muscle cells called myoglobin which accepts, stores and releases oxygen. 

Iron is also a component of some enzymes involved in collagen synthesis and proteins essential for energy metabolism and breathing. 

While the average adult male has about 1,000 mg of stored iron, women on average have about 300 mg of stored iron. Eating foods low in iron can cause the depletion of the iron stores in the body leading to iron deficiency anaemia. 

Iron deficiency anaemia is a type of anaemia caused by inadequate healthy red blood cells. It occurs when the body doesn’t have enough iron to make haemoglobin.

So what happens to the body when there is a low iron level? When iron is lacking in the body, it affects the body adversely in certain ways. You may not know what is wrong with you until you see a doctor. Telling your doctor the symptoms you are experiencing will help in the diagnosis.

Common side effects of iron deficiency

Below are some effects of low iron on the body.

Pale skin

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Iron deficiency can cause your skin to be paler than usual (also called pallor), including the inside of your lower eyelids.

Because haemoglobin in red blood cells gives blood its red pigmentation, reduced haemoglobin as a result of iron deficiency will make the colour of blood less red, which is why the skin looks paler.

You may notice the paleness all over your body or in certain parts like the gums, face, nails, inside the lower eyes and lips.

Even though the only way to confirm iron deficiency is by running a blood test, the paleness of the skin is often among the first things doctors look out for when diagnosing iron deficiency.

Restless leg syndrome (RLS)

A low iron level in the body has been linked to restless leg syndrome. Restless leg syndrome is a nervous system disorder that causes you to have a strong, uncontrollable urge to move your legs. It is usually due to uncomfortable sensations or itchiness in the legs.

Restless leg syndrome is usually worse at night and can affect a person’s sleep by making it difficult to fall asleep.

Iron deficiency anaemia is one of the secondary causes of restless leg syndrome. According to a 2020 study that investigated the prevalence of non-anaemic iron deficiency in people with RLS, people with iron deficiency were 6 times more likely to have RLS than people that were not deficient.

Constant unusual tiredness

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Iron deficiency can cause a person to be exhausted. It is one of the common side effects of iron deficiency. 

The fatigue that comes with iron deficiency is because there is not enough iron to make haemoglobin needed to transport oxygen all over the body. This results in less oxygen getting to the muscles and tissues.

When the muscles, tissues and cells cannot get enough oxygen, they get deprived of energy. The heart gets affected, too, as it has to do extra work to get more oxygen-containing blood transported around the body.

You may associate your constant tiredness with your busy life and stress. However, tiredness accompanied by irritability and difficulty concentrating gives a more substantial clue of iron deficiency.

Heart palpitations

Heart palpitation is the feeling of your heart beating, racing and pounding fast. It also happens when you feel like you skipped a heartbeat. Iron deficiency can cause heart palpitations.

According to a 2015 study of cardiac events in 166 patients with persistent atrial fibrillation, the association between iron deficiency anaemia and heart issues may be linked to oxygen supply.

Because the heart has to do extra work to circulate oxygen to all parts of the body when the iron level is low, the heart may start to beat irregularly, or you may start feeling your heart beating abnormally fast.

Also, if you have heart problems like coronary heart disease and heart failure, iron deficiency may worsen the condition.1 

Brittle/damaged skin and hair

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A reduced level of haemoglobin in the blood may reduce the amount of oxygen available to the skin and hair cells, causing the skin and hair to get dry, weak, and damaged. This is why iron deficiency is also associated with hair loss. 

This shows that your hair can give you clues about what is going on in your body. While it is normal to lose small amounts of hair when you comb or wash your hair, losing larger hair clumps may be a sign of iron deficiency. 

Brittle fingernails

Like your hair, your nails can also tell some things about your health. One of the effects of iron deficiency is brittle nails or spoon-shaped nails (also called koilonychia). 

Spoon-shaped nails are nails that look like their centre is scooped out, causing the nails to be thin and their edges to point upwards. 

Initially, iron deficiency usually causes the nails to be brittle and crack easily. Later, if the deficiency issue is not addressed, the brittle nails can further develop into spoon-shaped nails. 

Other things that may signal iron deficiency include depression, cold hands and feet, poor appetite and frequent infections.

Iron deficiency can also cause neurological effects like restless leg syndrome and attention deficit hyperactivity disorder (ADHD) in children.

Aside from inadequate dietary intake of iron, iron deficiency can be caused by other underlying conditions such as inflammatory bowel disease, celiac disease, and loss of too much blood due to internal bleeding and heavy periods. 

This is why you must see your doctor once you notice something abnormal about your body. Aside from the fact that you are experiencing discomforting symptoms, you may be affected by an underlying medical condition that needs to be treated right away. 


  1. Anand, Inder S, and Pankaj Gupta. “Anemia and Iron Deficiency in Heart Failure: Current Concepts and Emerging Therapies.” Circulation vol. 138,1 (2018): 80-98. 
  2. Auerbach, Michael, and John W Adamson. “How we diagnose and treat iron deficiency anemia.American journal of hematology vol. 91,1 (2016): 31-8. 
  3. Lee, Wen-Hsien et al. “Anemia as an Independent Predictor of Adverse Cardiac Outcomes in Patients with Atrial Fibrillation.” International journal of medical sciences vol. 12,8 618-24. 16 Jul. 2015.
  4. Mattiello, Veneranda et al. “Diagnosis and management of iron deficiency in children with or without anemia: consensus recommendations of the SPOG Pediatric Hematology Working Group.” European journal of pediatrics vol. 179,4 (2020): 527-545. 
  5. UCSF Health. (n.d.). Hemoglobin and functions of iron
  6. Zhu, Xiao-Ying et al. “Correlates of Nonanemic Iron Deficiency in Restless Legs Syndrome.Frontiers in neurology vol. 11 298. 30 Apr. 2020.