Iron is Essential for Living

Just as iron is essential in the production of steel, it is also essential to human life. About 70% of the iron in your body can be found in a protein in red blood cells called hemoglobin.

Another 25% of the iron is stored in your body in a blood protein called ferritin. If your iron levels are too high or too low, they can cause serious health problems.

Why is Iron Important?

Iron is a mineral that the body needs for growth and development. It helps maintain healthy blood to carry oxygen around the body.

It is needed to produce healthy red blood cells and for proper hemoglobin function. Hemoglobin is the protein inside red blood cells that carries oxygen from our lungs around to all parts of our bodies. 

It transfers oxygen in the blood to our tissues and organs and then carries carbon dioxide from our organs and tissues back to the lungs. This helps the body to function properly providing oxygen to the muscles and brain to support energy levels, as well as physical and mental performance.

Iron helps combat fatigue while supporting good cognitive function and the immune system. It is also needed for body growth and development.

A lack of iron can lead to iron deficiency anemia. With insufficient iron, there would not be enough red blood cells to carry oxygen around the body, which would result in fatigue and poor well-being.

Iron and Immunity

Recently, there have been several important advances that have shed light on the mechanisms that regulate mammalian iron metabolism. Iron is essential for almost all living organisms and takes part in a number of important biological processes. 

Its ability to switch between multiple oxidation states makes it an important cofactor in electron transfer and oxidation-reduction reactions and also allows it to interact reversibly with other atoms, especially oxygen, Sulphur, and nitrogen. 

Mammals have evolved mechanisms for precise regulation of extra- and intracellular iron levels.

Iron deficiency has been reported to be associated with increased susceptibility to infection in both humans and experimental animals.

Iron and Vaccine Efficacy

Iron deficiency not only causes anemia but also may impair adaptive immunity and thereby vaccine efficacy. Adaptive immunity is vital as it is the portion of our immune system that attacks and destroys pathogenic invaders and then creates an immune remembrance for the pathogen when our body encounters it in the future.

One study published in the Journal of Hematology, Sept 2021, revealed that those who had iron deficiency anemia had lower vaccine-induced antibodies compared to their non-iron deficient counterparts. Another study in Kenya suggested that the availability of iron in the blood was a limiting factor for vaccine efficacy. 

Iron deficiency anemia at time of vaccination predicts decreased vaccine response and iron supplementation at time of vaccination increases humoral vaccine response. Over 40% of children <5 y worldwide are anemic, many due to iron deficiency.

In relation to Covid-19 vaccines, it is advisable to correct the iron deficiency before administration of the Covid-19 vaccine.

Can Iron be Harmful?

Yes, iron can be harmful if you get too much. The functions of iron are mainly based on its ability to donate electrons, which also allows for the production of free radicals, which are potentially toxic for the host or the invaders. Iron is thus both essential for living and potentially toxic.

In healthy people, taking high doses of iron supplements (especially on an empty stomach) can cause an upset stomach, constipation, nausea, abdominal pain, vomiting, and diarrhea. Large amounts of iron might also cause more serious effects, including inflammation of the stomach lining and ulcers.

Free iron can be cytotoxic when present at high concentrations because it can catalyze the formation of oxidative radicals that damage proteins, lipids, and nucleic acids. Thus, both iron deficiency and iron excess can have adverse effects on a variety of cell, tissue, and organ functions.

Iron overload is less frequently seen but affects significant numbers of people in the form of hereditary hemochromatosis or in association with hemolytic anemias, repeated blood transfusions, dietary excess, certain infections, and alcoholic liver disease.

High doses of iron can also decrease zinc absorption. Extremely high doses of iron can cause organ failure, coma, convulsions, and death. Child-proof packaging and warning labels on iron supplements have greatly reduced the number of accidental iron poisonings in children.

Anemia of Chronic Disease

Macrophages play an important role in host defense against invading bacterial pathogens and a central role in iron homeostasis since they engulf senescent red blood cells and recycle iron for erythropoiesis. 

In response to infection the host limits the bioavailability of iron, limits iron uptake from the gut and retains iron in macrophages. The host also limits the egress of iron from macrophages.

Retaining iron in macrophages if prolonged can cause iron maldistribution which is known as anemia of chronic disease. This altered iron homeostasis is associated with many chronic inflammatory and degenerative diseases.

Some chronic diseases—such as rheumatoid arthritis, inflammatory bowel disease, and some types of cancer—can interfere with the body’s ability to use its stored iron. Taking more iron from foods or supplements usually does not reduce the resulting anemia of chronic disease because iron is diverted from the blood circulation to storage sites. The main therapy for anemia of chronic disease is treatment of the underlying disease.

Hemochromatosis

Hemochromatosis, or iron overload, is a condition in which the body stores too much iron. It’s often genetic. Hemochromatosis causes the body to absorb too much iron from the food. Excess iron is stored in organs, especially the liver, heart, and pancreas. It can cause serious damage to the heart, liver, and pancreas.

Symptoms may include joint pain, abdominal pain, fatigue weakness, diabetes, loss of sex drive, impotence, heart failure, liver failure, bronze or gray skin color, and memory fog.

The most common type of hemochromatosis is present at birth. But most people don't experience symptoms until later in life — usually after age 40 in men and after age 60 in women.

Without medical treatment, people with hereditary hemochromatosis can develop serious problems such as liver cirrhosis, liver cancer, and heart disease. People with this disorder should avoid using iron supplements and vitamin C supplements.

Iron Acquisition by Pathogenic Microbes

Iron is an essential nutrient for nearly all bacterial species that infect humans. Bacterial pathogens must therefore possess mechanisms to overcome iron-withholding defenses in order to successfully colonize humans.

For most microorganisms iron is an essential element since it is involved in many reactions in the cell. Iron is a transition element and the fourth most abundant element in the Earth's crust. Iron is vital for growth of nearly all living organisms, from prokaryotes to humans. Iron plays an important role in several cellular processes, such as respiration, photosynthesis, oxygen transport, and DNA synthesis. Iron is essential but it is not easily bioavailable; ferric iron solubility is low at physiological pH whereas ferrous iron, in aerobic environments, is highly toxic. Therefore, iron is normally bound to proteins and the whole body and cellular iron concentrations have to be regulated in all organisms.

Iron is an abundant element, but it is not always available. Pathogenic microorganisms such as bacteria and fungi are confronted with the problem of iron sequestration by lactoferrin in secretions and transferrin in blood while the remaining iron is intracellular in hemoproteins or associated with proteins such as ferritins.

Therefore, during infection, there is a constant battle between the host and the invader for iron, in which the invader attempts to have access to host iron and the host arranges complex iron-withholding mechanisms to frustrate the iron stealing.

Parasites depend absolutely on host iron for survival and often have a high iron requirement for growth, metabolism, and virulence.

Sources of Iron

Our bodies don’t produce iron by themselves and also lose it through a number of ways including menstruation, urination, defecation, sweat and the exfoliation of dead skin cells. Iron deficiency is the most common nutritional deficiency in the world. This means we need to consume sufficient amounts of it as part of a healthy balanced diet.

Good sources of iron include dietary supplements and foods rich in iron. These include red meat, poultry, seafood, fish, shellfish, spinach, broccoli, liver, organ meats, kidney beans, chickpeas, eggs, legumes, nuts, and dark chocolate.

Your body absorbs iron from plant sources better when you eat it with meat, poultry, seafood, and foods that contain vitamin C, such as citrus fruits, strawberries, sweet peppers, tomatoes, and broccoli.

All the dry fruits, raisins, dates, apricots, almonds, fig works great to deal with iron deficiency in the body. They are healthy and really helpful in improving blood cell count by boosting the hemoglobin levels in the body.