What to know about iron deficiency anaemia

Iron is an essential nutrient that is needed by your body to maintain energy levels and keep you healthy. Iron is also essential for growth and development in children and to help support your immune system. Iron is used by your body to make two proteins:

• Hemoglobin - a protein in red blood cells that carries oxygen around your body
• Myoglobin - a protein that supplies oxygen to your muscles

Iron deficiency, however, is the most common nutritional disorder worldwide. Iron deficiency occurs when there is a decrease in the total amount of iron in the body. If iron deficiency is left untreated it can progress to iron deficiency anaemia, which is when iron levels have fallen so low that the production of red blood cells is affected.

A lack of iron can cause ongoing health problems. However, iron deficiency can be treated by diet, oral supplements, or in severe cases by intravenous (IV) iron or a blood transfusion.

Signs and symptoms of iron deficiency anaemia

Iron deficiency can occur with no symptoms, or vague, non-specific symptoms. As iron deficiency progresses, iron deficiency anaemia can develop. Symptoms of iron deficiency anaemia include:

• Pale skin
• Fatigue and tiredness
• Weakness and dizziness
• Difficulty concentrating
• Headaches
• Rapid heart beat
• Shortness of breath
• Inflamed or sore tongue
• Dry skin and hair, brittle nails
• Cold hands and feet
• Pica - an eating disorder that makes you crave items that are not thought of as food and have no nutritional value such as ice, hair, dirt, paper.
• Restless leg syndrome (RSL) - a constant need to move your legs especially when not doing anything active or at night. RSL can impact your quality of sleep.

What causes iron deficiency anaemia?

Iron deficiency anaemia is usually a condition that develops over a period of time, but depending on the cause it can also develop suddenly. Causes of iron deficiency anaemia include:

• Blood loss. Heavy menstruation, frequent blood noses, or slow, chronic bleeding caused by a peptic ulcer or colon polyps can cause anaemia.
• Eating a diet lacking in iron-rich foods. This is more common in people who are vegetarian or vegan.
• Digestive disorders. Coeliac disease and inflammatory bowel disease, for example, can lead to poor iron absorption.
• Cancer. Certain cancers can lead to anaemia because of blood loss, while others affect the development of red blood cells.
• Medicines that reduce stomach acid. These can reduce iron absorption and include proton pump inhibitors such as lansoprazole (Prevacid) and omeprazole (Prilosec). Other medications, such as aspirin, which can cause bleeding, can also reduce iron stores.
• Frequent blood donations
• Major surgery or physical trauma resulting in blood loss
• Gastric bypass surgery

How much iron do I need each day?

Some people are more at risk of iron deficiency anaemia than others, which means they need to take extra care to get the right amount of iron, including:

• Infants and children - need iron to support cognitive development and for growth spurts. A lack of iron may cause a child to be more susceptible to infection.
• Pregnant women - need enough iron to support themselves, as well as a growing baby. If iron levels are too low, it can increase the risk of premature birth and low birth weight.
• Breastfeeding women
• Athletes - like endurance runners, require a high amount of iron because it is needed for carrying oxygen and for energy metabolism. They also need iron to replace what they lose from the breakdown of red blood cells that occurs due to strong muscle contractions and impacts from the activity, such as feet repeatedly hitting the ground.

The guide below shows the recommended amount of iron needed per day for different life stages.

Recommended daily iron requirements

^{* Women have higher requirements for iron due to menstrual loss.}

It’s important not to take too much iron

Too much iron can be toxic, so it’s important not to exceed the upper limits of:

• 40 mg/day for babies and children up to 13 years of age
• 45 mg/day for adults and children aged 14 years of age and over

The body tightly controls the uptake of iron from the digestive system to help avoid excess iron being absorbed. The iron regulatory hormone hepcidin is responsible for regulating the amount of iron that is absorbed.

When the amount of stored iron in the body is high, hepcidin levels increase causing the body to reduce the amount of iron that is absorbed. When iron stores are low, hepcidin levels fall allowing the body to absorb more iron.

Symptoms of iron toxicity or poisoning initially include gastrointestinal symptoms, such as stomach pain, vomiting, diarrhea, vomiting blood and passing blood when you pass a stool. If left untreated, iron toxicity can lead to liver and kidney failure, heart damage and more.

Symptoms of iron overload (haemochromatosis), a condition in which iron levels in the body build up too much over time, include fatigue, weakness, joint pain, darkening of the skin, low sex drive and weight loss. If left untreated, iron overload can cause organ damage, including to the liver, heart and pancreas.

Contact your healthcare provider straight away if you think you may have taken too much iron.

How is iron deficiency anaemia diagnosed?

Simple blood tests can be used to test for iron deficiency and iron deficiency anaemia. The blood tests include:

• A full blood count or complete blood count (CBC) which measures:
  • Hemoglobin levels - Hemoglobin is a protein found in red blood cells that carries oxygen. A low hemoglobin level is a sign of anaemia.
  • Hematocrit levels - Hematocrit measures the proportion of blood that consists of red blood cells or how much space there is between red blood cells. A low hematocrit level is a sign of anaemia.
  • Mean corpuscular volume (MVC) - Measures the size of the red blood cells. If they are smaller than normal it suggests iron deficiency anaemia.
  • Red blood cell counts
  • White blood cell and platelet counts - can help identify signs of infection, blood disorders and other issues.
• Reticulocyte count - Measures the amount of reticulocytes - very young red blood cells - and shows if your bone marrow is making red blood cells at the necessary rate.
• Peripheral smear - Looks at a sample of your blood under a microscope to see if your red blood cells look smaller and paler than normal, which indicates iron deficiency anaemia.
• Iron level tests which measure:
  • Serum iron - Measures the amount of iron in the blood. Serum iron levels can be normal even when total body levels are low.
  • Serum ferritin - Ferritin is a protein that stores iron in the body. Low ferritin levels indicate your iron stores are being used.
  • Transferrin level or total iron-binding capacity (TIBC) - Transferrin is a protein that carries iron in the blood. TIBC measures how much of your transferrin is carrying iron. High levels of transferrin without iron indicate iron deficiency anaemia.

How is iron deficiency treated?

Treatment for iron deficiency will depend on the cause and whether or not it has progressed to iron deficiency anaemia. Treatments options include:

Diet

A change in diet may be all that is needed to boost your iron levels, particularly if you’ve had a diet that is lacking in iron-rich foods.

• Eat more iron-rich foods. Food has two types of iron - heme and non-heme.
  • Heme iron food has a greater level of iron that is more easily absorbed and is found in meat, poultry and seafood.
  • Non-heme iron is found in vegetables, beans, lentils, nuts and iron-fortified food and is absorbed less easily than heme iron foods, but it is still essential for a healthy diet.
• Eat more food with vitamin C, such as tomatoes, citrus fruits and peppers. Vitamin C can help iron be absorbed more easily if eaten at the same time.
• Have less of the foods and drinks that prevent iron absorption. Coffee, tea, wine and dairy products such as cheese, milk and yoghurt can inhibit iron uptake. It is best to consume these foods and beverages between meals.

The tables below give examples of how much iron is in different foods.

Iron supplements

Iron supplements, also known as iron pills or oral iron, may be needed if diet alone is not boosting your iron levels. These are taken by mouth, ideally with some vitamin C to improve absorption. Ideally iron supplements should be taken on an empty stomach - one hour before food or two hours after - to help you absorb the iron. They can, however, be taken with food if they cause a stomach upset. Your healthcare professional will prescribe the dosage that is right for you. It can take weeks to months to correct iron deficiency and build up your iron stores.

Side effects of iron supplement include:

• Constipation
• Diarrhea
• Vomiting
• Upset stomach
• Metallic taste in your mouth

Intravenous infusion of iron

An intravenous (IV) iron infusion may be recommended if you can’t tolerate oral iron supplements or do not respond to them.

An IV infusion is delivered via a needle through a blood vessel and increases iron levels quickly. It may be needed for people with chronic blood loss, long-term health issues, heart or kidney problems, after surgery or after giving birth. Side effects of an IV iron infusion include vomiting, headache, hives or itchy skin.

Blood transfusion

A blood transfusion is used when iron stores and red blood cells are severely depleted and urgently needed. A transfusion of donated red blood cells or blood components is administered via a vein to quickly boost red blood cell and iron levels. It is a temporary measure till the source of the deficiency is determined.

Bottom line

• See your healthcare provider if you think you may be iron deficient
• Eat a balanced, mixed diet of meat and plant-based food to help avoid iron deficiency. If you do not eat meat or fish, make sure you include foods such as tofu and iron-fortified foods into your diet that are rich in non-heme iron
• Take iron supplements on an empty stomach if possible
• Get repeat blood tests as recommended by your healthcare provider to check your iron levels