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Writer's pictureKim Atherton

Iron Deficiency Anaemia Explained

Updated: Dec 12, 2023

Iron Deficiency Anaemia is described as the most common form of anaemia. Inadequate levels of the essential mineral Iron in the body, lead to a decreased production of haemoglobin. This in turn leads to a reduced production of red blood cell (RBC), resulting in Iron Deficiency Anaemia. Symptoms are then related to the extent of the reduction in RBC.

A diagrammatic representation of red blood cells showing iron deficiency anaemia
Iron deficiency Anaemia affects RBC in many ways as shown on this peripheral blood smear illustration.

Iron Deficiency Anaemia symptoms explained


Iron Deficiency Anaemia can present with many signs and symptoms and are explained below:

  • Weakness

  • Fatigue

  • Irritability and mood swings

  • Headache

  • Exercise intolerance

  • Cravings for non-food items (Pica)

  • Pallor

  • Shortness of breath

  • Restless legs syndrome

  • Poor digestion (either by low gastric acid causing iron deficiency, or iron deficiency causing low gastric acid)

  • Hair loss

  • Reduced thyroid function (Hypothyroidism) as iron is needed for thyroid function

  • Impaired immune function

  • Depression

  • Infertility

  • Dizziness

  • Decreased mental and motor function

  • Severe iron deficiency may result in Tachycardia (elevated heart rate) from the lack of oxygen as RBC are required to supply haemoglobin, which is in turn required for oxygen delivery to the body


Specific Signs and Symptoms of Iron Deficiency Anaemia:


  • Brittle or spoon-shaped nails (Koilonychia)

  • Swollen or sore tongue

  • Cracks or ulcers at the sides of the mouth

  • Unusual non-food cravings (pica) - for items like ice and dirt

Picture shows a concave or spoon shaped fingernail which is specific for iron deficiency anaemia
Koilonychia (spoon shaped) fingernail specific for iron deficiency anaemia.

Laboratory Testing for Iron Deficiency


Laboratory test results will provide the differential diagnosis for iron deficiency anaemia. If Iron-Deficiency Anaemia is suspected a Full Blood Count (FBC) and Iron Studies will be performed.


A. Full Blood Count (FBC):

  • Full Blood Count (FBC) will show a reduced RBC count, and reduced haemoglobin (Hb)

  • Reduced size of RBC or mean corpuscular volume (MCV) Reduced oxygen carrying haemoglobin concentration or MCHC

  • Reduced haematocrit (Hct)

  • RBC may show anisocytosis (different sizes), and an increased red cell distribution width (RDW) highlighting RBC at various stages of development or past iron treatment

  • RBC reflect microcytic (small), hypochromic (pale) anaemia which is the advanced diagnostic findings of iron deficiency anaemia

  • Platelet levels will begin to rise

B. Iron studies:

Iron Deficiency Anaemia

Iron levels

Transferrin

TIBC

% Saturation

Ferritin

Results

Low

High

High

Low

Low

Table showing the different markers for detecting Iron Deficiency Anaemia


C. Ferritin testing:

The intracellular iron storage, Ferritin, is the gold standard testing and will show low Ferritin levels. However, Ferritin levels may be falsely raised in inflammation, lead poisoning and malignancy.


D. Other Pathology Tests:

  • Coeliac testing

  • H. pylori investigation

  • Inflammatory Bowel Disease screening

  • Gastric Parietal Cell Antibody screening

  • Faecal occult blood studies

  • C-reactive protein testing for inflammation

  • ESR will be elevated due to anaemia

  • Thyroid Function Tests (see Fun Fact below)

Progression of Iron Deficiency in Pathology testing:


Stage 1: Characterized by decreased bone marrow iron stores. Haemoglobin (Hb) and serum iron remain normal, but the serum ferritin level falls to < 20 ng/ml. The compensatory increase in iron absorption causes an increase in iron-binding capacity (transferrin level).


Stage 2: Erythropoiesis (Red Blood Cell production) is impaired. Although the transferrin level is increased, the serum iron level decreases and transferrin saturation decreases.


Stage 3: Anaemia with normal-appearing RBCs and indices develops.


Stage 4: RBC microcytosis and then hypochromia develop.


Stage 5: Iron deficiency affects tissues, resulting in symptoms and signs.



Causes of Iron Deficiency

Causes of Iron Deficiency Anaemia can be grouped into the following classifications as either an Increased Iron Need, Decreased Iron Availability, or Refractory Iron Deficiency.


1. Increased Iron Need:

  • Iron loss through RBC loss (menorrhagia, gastrointestinal bleeding, GI tract cancer, peptic ulcers, haemorrhoids, post-partum, ulcerative colitis)

  • Higher iron demands at various stages of life like pregnancy for foetal development, lactation, young children, and teenagers, extreme exercise where increased erythropoiesis is required

2. Decreased Iron Availability:

  • Low intake of iron (malnutrition, vegetarian diet)

  • Poor absorption of iron (inflammation, obesity, Coeliac disease from a defective mucosal barrier, or low stomach HCl.

  • Ingesting competitors that chelate iron such as calcium, lead, cobalt, phytates, tannins, phenolics.

  • Ingesting predators like H.pylori that can cause refractory iron deficiency anaemia, parasites and worms in the GIT.

  • Achlorhydria from gastric parietal cell dysfunction.

  • Medications that alter gastric pH can also decrease iron absorption - these include antacids, proton pump inhibitors, and H2 blockers (Zantac).

3. Refractory Iron Deficiency Anaemia (IRIDA) and Inflammation:

  • Hepcidin is the central regulator of Iron haemostasis. Hepcidin deficiency causes iron overload, while Hepcidin excess is associated with iron-refractory iron deficiency anaemia which is resistant to improvement, inflammation and chronic kidney disease.

Oral iron supplemetation upregulates Hepcidin. Hepcidin then limits the absorption of high-dose oral iron supplementation, as the body recognises high dose iron as inflammatory.
  • If there is inflammation, iron will be removed from the blood and taken back to the liver, so it's not available. This is a protective mechanism. If for example we have parasites and they are consuming our iron, then our body in that inflammatory state attempts to starve the parasite of iron.

  • Iron is then stored in the liver as Ferritin, so adequate Ferritin levels can also be indicative of the inflammation which has caused the iron to be stored. (see Hepcidin discussion below).

  • There is now an understanding that there are opposing aspects of iron absorption. The need for many physiological processes versus the threat it poses by encouraging and ‘feeding’ pathogen growth like parasites for example.

Existing data suggests that hepcidin balances the need for iron, against the threat of pathogen growth and infection.

Flow chart showing how an increased iron demand, decreased iron intake, chronic blood loss and inflammation can cause iron deficiency anaemia
Flow chart highlights the various causes of iron deficiency anaemia.

Therapeutic goals
  • Treatment involves resolving and improving your iron deficiency, and importantly, understanding, and addressing the underlying aetiology.

  • In people with chronic inflammatory conditions, response to oral iron therapy may be limited by the hepcidin-mediated decreased absorption. As such the objective is to reduce the cause of inflammation first.

  • While medically important to correct iron deficiency, there is increasing evidence that boluses of iron work against the body’s developed haemostasis mechanism. Hepcidin restricts iron availability due potentially to the presence of pathogenic bacteria in the GIT. Hence the need to understand the aetiology, and to not let iron deficiency get so low that an iron infusion is necessary.

Fun Fact 1: Iron is needed for clotting. If you have low iron and are a menstruating female, the fact that you have low iron could be why you have heavy menstrual periods - and not the other way around!

Treatment goals are aimed at:

  • Understanding the reason behind the anaemia, and improve through diet, corrective actions and supplementation

  • Understanding your diet - do you have low protein intake?

  • Understand circumstances (pregnancy, lactation, exercise), or known current diseases (ulcers etc) or any relevant history (colon cancer etc).

  • Is there medication use?

  • Determine if it is:

    • Chronic blood loss from menstruation via a menstruation summary or charts

    • GI bleeding (via faecal occult blood testing)

    • Obtain an understanding of bowel movements and have a Complete Microbiome Mapping from stool sample to understand pathogen presence (H. pylori, worms, parasites) that may be competing for iron needs.

    • Undertake Coeliac testing to determine if gluten in the diet is destroying the absorption capability of iron, or reason behind poor absorption of iron

    • Understanding your intake of iron for intestinal absorption

    • Administering supplemental iron (if required), and providing therapeutic strategies for the gut to improve poor absorption, reduce inflammation, and enhance iron levels and ferritin stores.

    • Do you chew food properly to stimulate gastric secretion of HCl, and digestive enzymes to break down food so you can absorb the nutrients?

Fun Fact2: Anaemia could be showing that you have thyroid concerns, as the thyroid gland controls all metabolism, including the lifecycle of RBC, and your digestion and absorption of nutrients.

Food Inclusions

  • Iron containing foods such as heme and non-heme foods

  • Heme sources – Liver, Oysters, Organic Red Meat

  • Non-heme sources - Legumes, whole grains, nuts, seeds, green leafy vegetables

  • Vitamin C taken at same time as non-heme foods to improve absorption

  • Herbal treatments that kill bacteria and parasites in GIT that feed off consumed dietary iron e.g., berberine, garlic

  • Foods that reduce inflammation to eliminate the hepcidin iron blockade process in the body to allow iron absorption at lower iron levels. This includes eating a diverse variety of colours from naturally occurring fruit and vegetables.

Food Exclusions

  • Gluten free diet if positive for Coeliac disease due to inflammatory effects on small intestinal microvilli. Even if testing shows you are negative, an inflammatory state on a heavy bread diet may result in high hepcidin levels that prevent iron absorption.

  • Remove tannins, polyphenols from tea, coffee, cocoa, wine, some spices, dairy, eggs, phytates in legumes, grains, rice, soy protein as they will chelate (bind). As a minimum consume away from iron foods or supplements

  • Separating taking of other supplements like calcium, magnesium, and zinc at different times of the day to iron supplementation as they chelate (bind) iron and prevent absorption

  • Dairy as it inhibits absorption of iron

  • Take iron supplements away from pharmaceutical medications due to chelating effects

  • Remove uncooked plant foods as oxalates compete with iron

  • Remove NSAID use, like Nurofen

Specific Dietary focus

  • Increase Gastric HCl by chewing foods better to ensure food is broken down to allow the absorption of nutrients

  • Decrease inflammatory foods like gluten, dairy, and sugar to reduce inflammation and hence hepcidin levels that prevent iron absorption

Specific Nutrients

  • Iron

  • Lactoferrin as assistance to iron absorption

  • Vitamin C to assist with iron absorption in non-heme foods

  • Garlic and Berberine for their antibacterial effects, removing competitive chelators

  • Broccoli for its antibacterial and antiviral effects, removing competitive chelators

  • Green tea inhibits the adhesive affects of H. pylori, is anti-bacterial and is also a powerful antioxidant

  • Red wine in moderation. Resveratrol is anti-bacterial

  • Liquorice for treating peptic ulcers and inhibiting colonisation of H. pylori

  • Manuka honey for anti-bacterial effects, removing competitive chelators

  • Probiotics to increase beneficial bacteria and compete with potential pathogenic bacteria that may be utilising iron. Members of the Lactobacillaceae and Bifidobacteriaceae families that have no requirement or a very low requirement for iron are the most beneficial

  • Get Vitamin D from the sun to lower Hepcidin levels

  • Anti-inflammatory herbs to lower hepcidin levels

  • Zinc

Fun fact 3: Low Ferritin can actually be a sign of Zinc Deficiency! Additionally, iron deficiency can cause zinc deficiency.
Fun fact 4: High Ferritin can simply be a sign of inflammation which is not desired.

Lifestyle Modifications

  • Lose weight if applicable, as obese people have greater systemic inflammation and circulating hepcidin levels and subsequent inability to absorb iron

  • Home-prepared meals versus highly processed inflammatory foods to reduce inflammation

  • Give up smoking, recreational drugs, minimise drinking alcohol if applicable for reducing inflammation

  • Spread-out coffee and tea consumption throughout the day if applicable, and consume away from food

  • Ensure chelating dietary choices are taken away from iron supplementation or iron containing foods

  • As Iron-deficiency anaemia can cause shortness of breath, tiredness and dizziness, exercise should be undertaken slowly.

Hopefully you've realised that iron deficiency is not as straight forward as supplementing with iron. Determining the causes is a huge component to identifying the right strategy.


If you would like to discuss your personal circumstances, or have your pathology results reviewed in line with your current situation, feel free to make a booking with me on the bookings tab on my website.



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