Your 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 part of haemoglobin is iron. Iron is an important dietary mineral found in the foods we eat and is essential for your body to do what it’s supposed to do.
Our bodies need iron to make haemoglobin, and for our general health and wellbeing.
Let’s take a closer look at iron and haemoglobin when it comes to donating blood.
When you donate blood, you give about 250mg of iron with your red cells.
Because you are donating iron, your iron levels can drop below the normal limits after one donation or over time.
Low iron can lead to fatigue, impaired concentration or difficulty exercising and may also lead to a low haemoglobin (anaemia) which may cause breathlessness and dizziness.
So it’s really important you have healthy iron stores before you donate and to replace your iron before your next donation, to keep you feeling your best.
Your body will replace the iron you lose through diet but for some donors this may take longer than the 12-week wait between blood donations.
If you think you might be low in iron, please visit a doctor to check your iron levels before giving blood.
How to maintain healthy iron stores
- If you donate blood, we recommend a healthy iron-enriched diet.
- Women aged 18-45 are particularly susceptible to low iron because of menstruation and pregnancy so we recommend a short course of iron supplements each time after you give blood.
- For other donors we recommend you speak with your doctor to see if iron supplements are suitable for you.
- Although you can give blood every 12 weeks, this may not be suitable because of the amount of iron you lose when you donate. If that’s true for you, consider donating less often or give plasma, which has a very small red cell and iron loss.
- If you’re planning for pregnancy, it’s especially important that you build and maintain healthy iron levels.
Remember, check in with your doctor if you have a history of low iron or think you may have low iron.
What do we measure and when?
In most of our blood donor centres, we’ll collect a few blood drops from a finger prick, but in some centres we’ll use a blood sample collected from the vein just before you donate.
This test will measure your red blood cells. When you give blood, you’re giving red cells, so you’ll have a temporary drop in your haemoglobin level. We just want to make sure your haemoglobin is high enough for you to safely donate.
Note: Haemoglobin doesn’t measure iron stores. In early iron deficiency, the haemoglobin will be normal. We don’t check your iron levels because there is currently no suitable testing device available to measure iron levels in our donor centres.
The minimum haemoglobin level needed to donate blood is 120g/L (grams per litre) for women and 130g/L for men.
Minimum level for plasma and platelets
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 because you get your red blood cells back during the donation. Find out more about donating plasma.
You won’t be able to donate on the day. If that happens, we’ll send a blood sample to our lab to measure your ferritin levels, which tells us your iron levels.
We do this because the most common cause of low haemoglobin is low iron. Other causes include blood loss (such as menstruation and blood donation) or deficiencies in B12 or folate. For some people, a level near the lower limit may be normal.
If you have low haemoglobin, low iron or both, we’ll recommend that you see your doctor and we'll send you a letter you can take with you.
Taking iron supplements
If you’re a woman aged 18-45 and donating blood, we recommend that you take a short course of iron supplements after your donation.
For more information, check out these frequently asked questions or download this flyer to find out more about our recommendations for iron supplements. Please read the flyer in full before purchasing iron supplements and consult your doctor if you have any concerns or questions.
- You’ve recommended iron supplements to me. Can I use a multivitamin instead?
While a lot of multivitamins do contain iron, most only have a small dose of elemental iron (e.g. 5mg per tablet). Multivitamins wouldn’t replace the iron you donated as quickly as one of the supplements we recommend.
If you’d prefer to use a lower dose iron supplement, speak with your pharmacist.
- Why do I have to tell the pharmacist if I’m taking medications?
Iron supplements can interact with some medicines when taken at the same time. The iron may change the effectiveness of your medication, or your medication may affect how your body absorbs the iron.
Your pharmacist can let you know if you need to take your iron supplement at a different time of day to your medicine.
- Why do I have to tell the pharmacist if I’m taking other supplements?
Many supplements already contain iron, including those for pre-pregnancy. Your pharmacist can let you know how much iron, if any, is in your current supplement and help you decide if you need more to help replace what you’ve given during donation.
If you’re taking a pre-pregnancy supplement, you should continue taking it — it also contains folate.
- Why isn’t Lifeblood providing or paying for the supplements?
Australian legislation doesn’t allow us to provide iron to donors. Only pharmacies can dispense these supplements.
- Why don’t you recommend taking iron supplements after a plasma donation?
When you give plasma, your red cells are returned to you. That means you don't give as much iron in your donation, and our research shows that plasma donors usually aren’t at an increased risk of low iron.
If I don’t menstruate and haven’t been pregnant recently, do I still need to take the iron?
We’re recommending iron for all women aged 18-45 regardless of menstrual or pregnancy history. Speak with your doctor if you’re not sure about your iron requirements.
- If I take iron can I donate blood more often?
No. For your health and wellbeing, you still need to wait 12 weeks between blood donations. It’s a different story for plasma, though! Learn more about giving plasma.
- My haemoglobin is normal, do I still need to take iron?
After donating, your body uses iron to make haemoglobin for new red cells. Your body will absorb the iron it needs from diet, but it can take months to get back to the level it was. A short course of iron supplements can help you maintain healthy iron levels, keeping you feeling your absolute best.
- Should I donate blood if I can’t, or choose not to, take iron supplements?
It’s really up to you, but it’s important that you consider your own health and wellbeing. Have a think about reducing how often you donate or try giving plasma instead, which has a smaller iron loss and bonus – when it comes to donating, it’s a game-changer.