Anaemia is characterised by a deficiency in the size or number of erythrocytes (red blood cells) or a reduction in the quantity of circulating haemoglobin. Haemoglobin is what gives the red colour to your blood; it contains iron and is responsible for the transport of oxygen around your body.
Iron deficiency anaemia is a common type of anemia caused by insufficient dietary intake and absorption of iron, and/or iron loss from bleeding which can originate from a range of sources such as the intestinal, uterine or urinary tract.
Iron deficiency anaemia is the cause of approximately half of all anemia cases worldwide and affects women more often than men. Iron deficiency anaemia can result if the body does not make enough red blood cells or bleeding causes loss of red blood cells more quickly than they can be replaced.
Causes of iron deficiency anaemia
- Inadequate iron intake. This is common in vegetarians, vegans or individuals who do not eat much meat or other iron-rich food sources. Skipping meals and dieting can also contribute to iron deficiency anaemia.
- Insufficient iron absorption. This can be due to a number of factors such as diarrhoea, coeliac disease or drug interference.
- Inability to meet increased requirements. An increase in iron requirements occurs simultaneously with an increase in blood volume which takes place during pregnancy, lactation and periods of growth. This increases the amount of iron you need from your diet.
- Increased iron loss. This can be as a result of menstruation in women, blood loss from injury or some chronic disorders/disease.
Symptoms of iron deficiency anaemia
- Fatigue, weakness
- Pale skin
- Orthostatic hypotension – A drop in blood pressure which occurs with postural change such as standing after being seated or lying. Often experienced by momentary light-headedness or slight distortion in vision
- Loss of appetite or food cravings
- Difficulty concentration, easily irritated
- Reddened tongue
Bioavailability of iron (degree of absorption)
- Haem iron: Available from animal sources such as meat, fish and poultry. This type of iron the best at being absorbed, with approximately 15% being available for absorption1. The redder the meat, the better the absorption.
- Non- haem iron: Can be obtained from meat and also grains, lentils, eggs, vegetables and fruit. Approximately 3 – 8% of non- haem iron is absorbable, but is dependent on the presence of foods that enhance iron absorption1.
- Foods that enhance iron absorption: These are foods that can increase the degree of iron absorbed from non-haem iron food, such as:
- Meat, fish, offal and poultry aid the absorption of non- haem iron when eaten in the same meal. For example, meat (particularly red meat) in combination with vegetables.
- Ascorbic acid binds to iron to form a readily absorbed compound. Aim to include a source of vitamin C with each meal e.g. orange juice.
- Vitamin A is responsible for releasing stored iron if the body is deficient. Foods such as sweet potato or carrots contain high amounts of vitamin A.
Foods that inhibit iron absorption:
- Avoid consuming tea, coffee or wine with meals. Certain properties in these products (tannins) bind to the iron, making it unavailable for absorption. Tea and coffee can reduce iron absorption by up to 75%!
- Do not consume milk with meals. Foods rich in calcium can also inhibit the absorption of iron.
- Soy protein and unrefined cereals can also reduce the amount of absorbable iron from non-haem foods e.g. bran cereal. This is due to the presence of phytates.
Iron supplements are generally needed during pregnancy to prevent iron deficiency anaemia. During pregnancy iron requirements are considerably higher than normal and without these you would need to consume all the required iron from the diet alone. Iron is tightly controlled within the body i.e. too little can be a problem, too much can be dangerous. Whilst supplements can be beneficial you should only take iron supplements as directed by your doctor, should you feel they are necessary.
- Include lean meats (where possible), legumes, dried beans, fresh fruit/dried fruit, vegetables and nuts in to your daily diet with fortified wholegrain breads and cereal. These have the greatest iron contribution of the non haem sources.
- Consume the above foods with items that enhance iron absorption e.g. sources of vitamin C such as orange juice, capsicum and tomato for example combining vitamin C with meals that contain grains or lentils increases their iron absorption.
- Avoid drinking tea, coffee and milk with meals
Iron deficiency anaemia may be due to medical problems. This article provides general advice and is not a substitute for thorough medical assessment. If you have iron deficiency anaemia see your local doctor. If you have iron deficiency anaemia due to a lack of iron in your diet – for more advice or information by an accredited practising dietitian, contact ENT Wellbeing on 1300 123 368 and make an appointment with our dietitian Belinda Elwin.