When most people think of the role of iron in human physiology, they think of the transport of oxygen via red blood cells throughout the body. And indeed, this is a key function of iron. However, iron has numerous other functions, including in maintaining a healthy immune system, and is a vital mineral for general health, wellbeing and vitality.
It can also be good for a cheeky pun every now and then. I’m not even sorry about the main picture – Steve
One of the main symptoms of low iron levels is fatigue. Mild iron deficiency is associated with feeling tired, a lack of energy and a pale complexion.
A more severe lack of iron in then body results in iron-deficiency anaemia, characterised primarily by:
Less common symptoms of iron-deficiency anaemia include brittle nails, thinning hair, itchy skin (pruritus), brain fog, dizziness or lightheadedness, mouth sores and ulcers, depression, restless legs, and wanting to eat non-food stuffs such as paper or ice (pica)[1]. Also, because of the role of iron in immune function, low iron can result in increased susceptibility to infection.
Causes of iron-deficiency anaemia include:
Animal-derived iron is referred to as haem-iron and is easily absorbed by the body.
Plant-derived iron is called non-haem-iron and is not well-absorbed. Vitamin C enhances its absorption, whereas phytates (found in bran cereals) and tannins (found in tea and coffee) further reduces its absorption; important for vegans and vegetarians to note.
The main food sources of iron include:
Functions of iron
Iron is needed by many different cell types in the body to perform very distinct functions.
Oxygen transport
A key function of iron is in oxygen transport. Haemoglobin, which is found within red blood cells, is a red protein that is responsible for transporting oxygen in the blood. Its molecule is made up of 4 subunits, each of which contains one iron atom that is bound to a haem group. The iron atoms bind oxygen, which is how haemoglobin within red blood cells transports oxygen from the lungs to every tissue and cell in the body.
As oxygen is necessary for cells to produce energy, a lack of oxygen getting to your cells due to iron deficiency (or due to defects in red bloods cells as seen with vitamin D and vitamin B12 deficiencies) results in fatigue.
Iron also has an important role in the process of making red blood cells (erythropoiesis), as well as in the production of haemoglobin.
Immune function
Another key area where iron has essential functions is in the immune system. This is why iron deficiency can result in an increased risk of infections. Of note, iron deficiency has also recently been linked to impaired immune responses to vaccines[1].
Iron is important for the development of numerous immune cell types, in particular T cells, and in the proper functioning of B and T cells (adaptive immune cells) in response to infection and vaccines.
Macrophages have an intricate relationship with iron; these immune cells tightly control the amounts of iron that are available for core biological functions while preventing its toxic effects on cells. Conversely, iron itself can directly regulate the immune functions of macrophages[1].
Iron also is directly involved in the killing of pathogens by immune cells, specifically neutrophils and eosinophils. Interesting, certain pathogens have developed ways to ‘hijack’ iron from immune cells and use it for their own growth and virulence.
Because of the demand for iron during an immune response and because the immune system actively sequesters iron away from invading pathogens, prolonged immune activation, due to infection, autoimmune disease or cancer, can result in a disorder called anaemia of inflammation (also called anaemia of chronic disease), which is the second most common form of anaemia worldwide after iron-deficiency anaemia. So, the balance of iron in the body is vital for maintaining health.
If you are interested in going on a deep dive into the role of iron in the immune system, you can check out this excellent review[2].
Muscles
Iron improves oxygen storage in muscle cells through myoglobin. Myoglobin is a protein containing iron that transports and stores oxygen within your muscles. Also, iron is involved in a metabolic process termed oxidative phosphorylation (OXPHOS) that limits lactate production and thus lactic acid accumulation. Thus, it is important for female athletes in particular to maintain adequate iron intake from their diet[3].
High-dose iron supplementation can have severe side effects and can be fatal for children. So, if you have been advised by your healthcare professional to take supplements containing iron, please ensure that the supplement is stored safely away from children and that the recommended dose is never exceeded.
If you would like to get find out more about your Thyroid levels, check out our Home Testing kit here
References
[1] Frost J. N., et al. (2021) Hepcidin-Mediated Hypoferremia Disrupts Immune Responses to Vaccination and Infection. Med (N Y). 2, 164-179.
[1] Soares, M. P., & Hamza, I. (2016). Macrophages and Iron Metabolism. Immunity, 44, 492–504.
[2] Cronin, S., Woolf, C. J., Weiss, G., & Penninger, J. M. (2019). The Role of Iron Regulation in Immunometabolism and Immune-Related Disease. Frontiers in molecular biosciences, 6, 116.
[3] Alaunyte, I., Stojceska, V. & Plunkett, A. (2015) Iron and the female athlete: a review of dietary treatment methods for improving iron status and exercise performance. J Int Soc Sports Nutr 12, 38.
Transform the way you approach your health with Hibernian Health Check’s convenient and accurate home blood test kits. In this post, we are answering the Top 10 Questions about Home Blood Testing Kits!
AMH stands for Anti-Müllerian Hormone and it is commonly viewed as a biomarker for ovarian reserve. The term ‘ovarian reserve’ refers to the reproductive potential in the ovaries based on the number and quality of follicles and oocytes (potential eggs) contained within.
When most people think of the role of iron in human physiology, they think of the transport of oxygen via red blood cells throughout the body. And indeed, this is a key function of iron. However, iron has numerous other functions, including in maintaining a healthy immune system, and is a vital mineral for general health, wellbeing and vitality.
It can also be good for a cheeky pun every now and then. I’m not even sorry about the main picture – Steve
One of the main symptoms of low iron levels is fatigue. Mild iron deficiency is associated with feeling tired, a lack of energy and a pale complexion.
A more severe lack of iron in then body results in iron-deficiency anaemia, characterised primarily by:
Less common symptoms of iron-deficiency anaemia include brittle nails, thinning hair, itchy skin (pruritus), brain fog, dizziness or lightheadedness, mouth sores and ulcers, depression, restless legs, and wanting to eat non-food stuffs such as paper or ice (pica)[1]. Also, because of the role of iron in immune function, low iron can result in increased susceptibility to infection.
Causes of iron-deficiency anaemia include:
Animal-derived iron is referred to as haem-iron and is easily absorbed by the body.
Plant-derived iron is called non-haem-iron and is not well-absorbed. Vitamin C enhances its absorption, whereas phytates (found in bran cereals) and tannins (found in tea and coffee) further reduces its absorption; important for vegans and vegetarians to note.
The main food sources of iron include:
Functions of iron
Iron is needed by many different cell types in the body to perform very distinct functions.
Oxygen transport
A key function of iron is in oxygen transport. Haemoglobin, which is found within red blood cells, is a red protein that is responsible for transporting oxygen in the blood. Its molecule is made up of 4 subunits, each of which contains one iron atom that is bound to a haem group. The iron atoms bind oxygen, which is how haemoglobin within red blood cells transports oxygen from the lungs to every tissue and cell in the body.
As oxygen is necessary for cells to produce energy, a lack of oxygen getting to your cells due to iron deficiency (or due to defects in red bloods cells as seen with vitamin D and vitamin B12 deficiencies) results in fatigue.
Iron also has an important role in the process of making red blood cells (erythropoiesis), as well as in the production of haemoglobin.
Immune function
Another key area where iron has essential functions is in the immune system. This is why iron deficiency can result in an increased risk of infections. Of note, iron deficiency has also recently been linked to impaired immune responses to vaccines[1].
Iron is important for the development of numerous immune cell types, in particular T cells, and in the proper functioning of B and T cells (adaptive immune cells) in response to infection and vaccines.
Macrophages have an intricate relationship with iron; these immune cells tightly control the amounts of iron that are available for core biological functions while preventing its toxic effects on cells. Conversely, iron itself can directly regulate the immune functions of macrophages[1].
Iron also is directly involved in the killing of pathogens by immune cells, specifically neutrophils and eosinophils. Interesting, certain pathogens have developed ways to ‘hijack’ iron from immune cells and use it for their own growth and virulence.
Because of the demand for iron during an immune response and because the immune system actively sequesters iron away from invading pathogens, prolonged immune activation, due to infection, autoimmune disease or cancer, can result in a disorder called anaemia of inflammation (also called anaemia of chronic disease), which is the second most common form of anaemia worldwide after iron-deficiency anaemia. So, the balance of iron in the body is vital for maintaining health.
If you are interested in going on a deep dive into the role of iron in the immune system, you can check out this excellent review[2].
Muscles
Iron improves oxygen storage in muscle cells through myoglobin. Myoglobin is a protein containing iron that transports and stores oxygen within your muscles. Also, iron is involved in a metabolic process termed oxidative phosphorylation (OXPHOS) that limits lactate production and thus lactic acid accumulation. Thus, it is important for female athletes in particular to maintain adequate iron intake from their diet[3].
High-dose iron supplementation can have severe side effects and can be fatal for children. So, if you have been advised by your healthcare professional to take supplements containing iron, please ensure that the supplement is stored safely away from children and that the recommended dose is never exceeded.
If you would like to get find out more about your Thyroid levels, check out our Home Testing kit here
References
[1] Frost J. N., et al. (2021) Hepcidin-Mediated Hypoferremia Disrupts Immune Responses to Vaccination and Infection. Med (N Y). 2, 164-179.
[1] Soares, M. P., & Hamza, I. (2016). Macrophages and Iron Metabolism. Immunity, 44, 492–504.
[2] Cronin, S., Woolf, C. J., Weiss, G., & Penninger, J. M. (2019). The Role of Iron Regulation in Immunometabolism and Immune-Related Disease. Frontiers in molecular biosciences, 6, 116.
[3] Alaunyte, I., Stojceska, V. & Plunkett, A. (2015) Iron and the female athlete: a review of dietary treatment methods for improving iron status and exercise performance. J Int Soc Sports Nutr 12, 38.
Olive gained her PhD in Trinity College Dublin in Immunology. She has enjoyed a varied career including working as an immunologist, researcher, science communicator and Chief Editor for leading scientific journal, Nature Reviews Immunology. Olive has now set up her own business in sustainable forestry management but still maintains her passion for science and education through her articles with Hibernian Health Check.
Transform the way you approach your health with Hibernian Health Check’s convenient and accurate home blood test kits. In this post, we are answering the Top 10 Questions about Home Blood Testing Kits!
AMH stands for Anti-Müllerian Hormone and it is commonly viewed as a biomarker for ovarian reserve. The term ‘ovarian reserve’ refers to the reproductive potential in the ovaries based on the number and quality of follicles and oocytes (potential eggs) contained within.
