Iron, haemoglobin and blood donation

Blood is rich in red cells that contain haemoglobin, a protein that carries oxygen from the lungs to the rest of the body. A key component of haemoglobin is iron. Iron is an important dietary mineral and is essential for your body to function normally.

When you donate whole blood, that donation contains some of your iron, which your body then replaces through your diet. The time taken to replace it depends on a number of factors, including your diet and your iron requirements.

Women aged 18-45 are particularly susceptible to becoming low in iron. find out more about replenishing iron for female donors.

FAQs about iron, haemoglobin and blood donation

What is haemoglobin? 

Haemoglobin is a protein in red blood cells that carries oxygen around the body. 
We measure yours before each donation. In most of our centres, this is done with a few blood drops collected from a finger prick, but some centres use a blood sample collected from the vein just before the donation. 

Is haemoglobin the same as iron?

No, but they are connected. Iron is an essential nutrient found in the foods we eat and is needed by our bodies to make haemoglobin. Iron is also needed for our general health and wellbeing. 

Why do you measure my haemoglobin before I donate blood?

Your health is important to us. When you give blood your donation contains some of your red cells, so you have a temporary drop in your haemoglobin level. We need to make sure your haemoglobin is high enough for you to donate safely.

What haemoglobin level do I need to donate?

The minimum haemoglobin level needed to donate whole blood is 120g/L for women and 130g/L for men. 

The minimum haemoglobin level to donate plasma or platelets is 115g/L for women and 125g/L for men. It’s lower for plasma and platelets as these donations have a much smaller red cell loss than a whole blood donation.

Does a normal haemoglobin level mean my iron levels are normal?

Not always. In early iron deficiency your haemoglobin will still be normal. 

Do you test my iron level before a donation?

Not usually. We only send a blood sample for iron testing if your haemoglobin level is below the minimum range required to donate or if you have a greater than 20g/L drop in haemoglobin since your last visit. 

Why don’t you test my iron?

There is currently no suitable testing device available to measure iron levels immediately before a donation.

What does it mean if I have low haemoglobin?

For some people a slightly low haemoglobin level may be normal. 

The most common cause of low haemoglobin is iron deficiency. Other causes include blood loss (such as blood donation) or deficiencies in B12 or folate. 

If your haemoglobin is low, we’ll postpone your donation and send a blood sample to our lab to measure your ferritin levels. Ferritin is the test that measures your iron levels. We’ll send you a letter containing the results. If you do have low haemoglobin and/or low iron, we’ll recommend that you see your doctor and we'll provide a letter you can take with you. 

Why is it important for me to have healthy iron levels?

When you donate blood, you donate red blood cells which contain iron. During a whole blood donation you give about 250mg of iron. Plasma and platelet donations have a much smaller iron loss.

Your body uses iron to produce the haemoglobin needed for new red blood cells. If you’re low in iron, your body will take longer to produce haemoglobin. If your haemoglobin level is below the normal range (known as anaemia), you might experience breathlessness and dizziness.

We need iron for our general health and wellbeing. If your iron becomes low (iron deficiency) you may develop symptoms such as fatigue or impaired concentration, or find you can’t exercise to your full capacity.

Is diet enough for me to maintain healthy iron levels?

Your body uses its iron to make the haemoglobin for replacement red blood cells. The time it takes to replace iron through your diet varies and will depend on your diet and general health. For some donors, this can take longer than the 12 weeks between donations. 

Who is at risk of low iron?

Women aged 18-45 are particularly susceptible to becoming low in iron due to menstruation and previous pregnancy. Frequent whole blood donors are also susceptible to becoming low in iron because it may take longer than the 12 weeks between donations to replace the iron.

If I’m low in iron will it affect my eligibility to donate?

Maybe. Iron is needed to make haemoglobin and to be eligible to donate, you need to meet our minimum haemoglobin level for the type of donation you’re making.  

Is it safe for me to donate whole blood?

Blood donation is safe for most people, however it may not be recommended depending on your individual health circumstances. Talk to your GP if you’re unsure whether whole blood donation is suitable for you.

What can I do to manage my iron health?

You should aim to have a healthy, iron-enriched diet. 

While iron is found in many of the foods we eat, some sources are better absorbed by the body than others. See our FAQ below to find out more about increasing iron absorption from your diet. 

If you’re a regular whole blood donor you may like to alternate whole blood and plasma donations, as you give much less iron when you donate plasma. Learn more about donating plasma .

Women aged 18-45 are particularly susceptible to becoming low in iron due to menstruation and previous pregnancy. We recommend a short course of oral iron supplements after each whole blood donation. Learn more about our recommendation by downloading the flyer below. Please read it in full before purchasing iron. If you have any concerns or questions, consult your doctor.

Download flyer 

Other donors should discuss the suitability of iron supplements with their doctor.

If you’re planning to become pregnant, it’s especially important that you build and maintain healthy iron levels to support the increased requirements of pregnancy. 

Speak with your doctor if you have any concerns about your iron levels or wish to discuss a suitable donation frequency. 

How can I increase my iron absorption from my diet?

A healthy, iron enriched diet is important for all donors, especially those who have an increased risk of iron deficiency. Although iron is found in many of the foods we eat, some sources of iron are better absorbed by the body than others.

There are two main types of iron in food:

  • Haem iron (found in animal foods such as red meat, seafood and poultry)
  • Non-haem iron (found in plant foods such as vegetables, legumes, wholegrain cereals, nuts and dried fruits)

About 20% of haem iron is absorbed compared with around 5% of non-haem iron.

Combinations of food can improve iron absorption. For instance, the absorption of non-haem iron can be improved by consuming it with:

  • Vitamin C (found in oranges, berries, kiwi fruit, grapefruit, tomato, broccoli and capsicum)
  • Organic acids (found in grapes, tomato, citrus fruits and pineapple)
  • Foods containing haem iron.

Some food combinations can reduce iron absorption if consumed with or within an hour of a meal, such as:

  • Calcium (found in dairy and soy)
  • Polyphenols (found in tea, coffee, cocoa and red wine)
  • Oxalic acid (found in spinach, rhubarb and sweet potato)
  • Phytates (found in cereals and legumes)

Try to choose foods high in absorbable iron at each meal, drink tea and coffee between meals rather than with meals and consider iron rich snacks, such as raisins, nuts, dates, prunes and figs.

Useful links and downloads  

We make these recommendations because your safety is important to us. Find out what else we do for donor safety

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