What is hemoglobin?
Hemoglobin is an iron containing protein that makes red blood cells red. Hemoglobin carries oxygen from our lungs to the cells in our body.
What are normal hemoglobin levels?
In women, normal hemoglobin ranges from 120 g/L to 160 g/L (12 g/dL to 16 g/dL). In men, normal hemoglobin levels range from 140 g/L to 180 g/L (14 g/dL to 18 g/dL).
Why is hemoglobin measured before each donation?
The hemoglobin screening test is done to make sure that it is safe for you to donate and that there are sufficient red cells for the person receiving your blood. Hemoglobin is checked before each donation using a drop of blood from your finger. For donors donating platelets by apheresis, a sample is taken from the first few drops of blood collected to measure hemoglobin.
What hemoglobin level do I need to donate?
Hemoglobin must be at least 125 g/L (12.5 g/dL) to donate blood at Canadian Blood Services.
I did not pass the fingerstick hemoglobin test – what does this mean?
There are a few possible reasons including:
- Low iron stores. Iron is needed to make hemoglobin.
Causes of low iron include:
- Frequent blood donation
- Low iron in your diet
- For women, menstrual blood loss
- More rarely, gradual bleeding in the digestive tract, such as stomach or colon
- Normal variation; for some people, especially women, a slightly lower hemoglobin level is normal and not the result of any health problem
- Sometimes the test may give a low estimate of the true amount of hemoglobin
What should I do if I failed my hemoglobin screen?
We recommend that you see your doctor to check your hemoglobin and iron levels (ferritin). Your doctor will look into reasons why your hemoglobin is low and may suggest taking iron supplements.
All blood donors should eat an iron rich diet and consider taking a multivitamin with iron.
Can I come back to donate if I failed my fingerstick hemoglobin?
Most people who have a low hemoglobin are able to improve their iron level and hemoglobin count and successfully donate.
It can take 4 to 6 months to rebuild your iron stores. Your doctor can help you decide when it is safe for you to donate again.
If your doctor has started you on iron pills, you may return to donate 6 months after starting them, when your hemoglobin and iron levels are back to normal.
What is iron and where do I get it from?
Iron is a mineral that is an important part of hemoglobin and other proteins in your body.
Your body gets iron from your diet. You can also get iron by taking multivitamins that contain some iron supplementation. Finally, the most iron is found in iron supplements.
Iron is essential to make new red blood cells after blood donation. Extra iron is stored as ferritin.
Is it possible to have normal hemoglobin but low iron?
Yes. You can have low amounts of iron with just enough to keep your hemoglobin level normal.
What are the effects of low iron levels?
Iron deficiency does not always cause symptoms. Low iron stores can lead to fatigue and less exercise capacity. Some people have a craving for ice. As iron levels drop more, your hemoglobin level could drop and this can have a big impact on your energy level.
Does Canadian Blood Services measure my iron levels?
Canadian Blood Services does not measure iron (ferritin) on every donation. However, starting in July 2014, Canadian Blood Services will be measuring ferritin in some selected donor clinics. Donors with low ferritin levels will be sent a letter with their results.
I got a result from Canadian Blood Services telling me that my ferritin levels are low. What should I do now?
We recommend that you see your doctor. He or she can check if you need any other tests done, and advise you about iron supplements. A diet rich in iron is recommended for all blood donors. However, since your ferritin level is low, iron supplements would be helpful to build up your iron stores.
You don’t need a prescription to get iron supplements. You can talk to your pharmacist about starting over the counter iron supplements if you cannot make an appointment to see your doctor right away. We recommend that you speak to your doctor first, before starting iron supplements, if:
- You have any gastrointestinal illness or symptoms, such as stomach ulcers, chronic constipation or diarrhea, or intestinal polyps.
- You are taking aspirin or anti-inflammatory pills (such as Advil or ibuprofen) regularly.
- You have family members with a history of colon cancer or polyps.
You should not take iron supplements if you have been diagnosed with hemochromatosis (iron overload) in the past.
Who is at risk of iron deficiency?
The chance of developing iron deficiency is higher in donors who:
- Had low iron levels before donation – iron levels are generally lower in women of child-bearing age.
- Make frequent donations – women donating 2 or more times a year, men donating 3 or more times a year.
- Have non-donation related blood loss, such as for women, heavy menstrual periods.
- Have a diet low in iron.
- Have medical conditions or surgery, which reduce the amount of iron the body can absorb.
Iron deficiency may be the result of more than one cause.
How can I improve my iron absorption?
Although iron is found in many foods, some sources of iron are better absorbed by the body. Iron comes in 2 forms:
- Heme iron, which is found in animal foods such as red meat, liver, veal, chicken, turkey, fish and seafood
- Non-heme iron, which is less easily absorbed and is found in breakfast cereals fortified with iron, fortified breads and pasta, lentils, dried peas and beans, tofu, seeds and nuts, dried fruit, dark green leafy vegetables and eggs.
I am taking iron, can I donate blood?
It depends why you are taking the supplements. If you have been told by your doctor that your iron reserves (ferritin) are low, or received a letter from Canadian Blood Services that your ferritin level is low, you can return to donate blood after you have taken iron supplements for at least 3 months, and your ferritin level has returned to normal, when remeasured by your doctor.
If you are taking iron supplements because your iron and your hemoglobin levels were low (iron deficiency anemia) you can return to donate after at least 6 months of taking iron supplements if your doctor has found that your hemoglobin and iron levels have returned to normal. If you are taking iron to prevent low iron stores, you can donate blood.
I have been diagnosed with hemochromatosis – should I donate?
People with hereditary hemochromatosis absorb too much iron from their diet. As long as there is no other reason why you cannot donate blood, regular blood donation can be both part of your treatment and help save lives. You can donate blood at Canadian Blood Services every 56 days. If you require phlebotomies more often than every 56 days, you can donate blood at least one week after a phlebotomy in your doctor’s office or outpatient clinic. More information can be found on the website of the Canadian Hemochromatosis Society (see related links).
Additional information for physicians – please see transfusionmedicine.ca, Iron status in Canadian Blood Services donors, for more information
All donors undergo hemoglobin screening prior to each donation, and will be deferred for 56 days if they do not meet the regulatory requirement for blood donation. Hemoglobin testing of whole blood donors is performed on a finger stick capillary blood sample using a portable hemoglobinometer. This method is less precise than a hemoglobin determination performed on a venepuncture sample and analysed in a laboratory. Low values may be obtained due to technical difficulties in obtaining a capillary sample, or measurement imprecision, rather than actual anemia. The regulatory requirement for whole blood donation in Canada is a minimum hemoglobin level of 125 g/L (12.5 g/dL).
Donor iron stores
Approximately 225 mg are lost with each whole blood donation of 525 ml. Female donors who donate 2 or more times a year, and male donors who donate 3 or more times a year are at higher risk of developing iron deficiency. We recommend measurement of ferritin in frequent blood donors, even if hemoglobin levels are normal. Iron supplementation and reduced frequency of donation may be indicated if iron stores are depleted. Additional investigations for underlying pathology may also be indicated, depending on a variety of factors, such as patient age and gender, symptoms or signs, and results of initial laboratory testing.
Deferred female donors
Approximately 10% of female donors do not meet hemoglobin criteria on a given donation attempt. Most of these individuals are iron deficient. These donors are advised to see their physicians in order to measure their ferritin levels and confirm the diagnosis of anemia on a venepuncture sample. If anemia is truly present, additional history and investigation may be indicated, and these individuals should be advised not to return to donate blood, unless the anemia is completely resolved and iron stores are adequate. Most of these individuals require a period of iron supplementation before resuming blood donation.
Deferred male donors
Less than 0.5% of male donors are deferred due to hemoglobin levels below the acceptability level of 125 g/L. As this is well below the normal hemoglobin level for males, these donors are advised to see their physicians in order to confirm the presence of anemia on a venepuncture sample. If anemia is confirmed, additional history and investigation may be indicated. In some cases, iron deficiency anemia may be related to extremely frequent blood donations. However, in other cases, underlying conditions leading to decreased iron absorption or gastrointestinal blood loss may be present. These individuals should be advised not to return to donate blood, unless investigations have been completed, anemia is resolved, and iron stores are adequate. Most of these individuals require iron supplementation before resuming blood donation.