What you need to know about hemoglobin, anemia, iron and hemochromatosis

Normal hemoglobin levels differ depending on several factors, including age, sex at birth, hormonal supplementation, altitude of residence as well as presence of different hemoglobin types that impact hemoglobin turnover and affinity for oxygen binding.

Normal hemoglobin levels have a wide range, usually from 120 g/L to 180 g/L.

For whole blood, platelets and some types of plasma donation, donors registered as male must have a hemoglobin level of at least 130 g/L and donors registered as female must have a hemoglobin level of at least 125 g/L.

For plasma donation, the hemoglobin level must be at least 125 g/L for all donors, regardless of gender at registration.

Blood donation, through removal of red blood cells, leads to removal of hemoglobin. Donors may develop low hemoglobin levels or anemia.

To ensure donors have sufficient blood levels after donation and to prevent anemia, a minimum hemoglobin level is required before each donation. This required hemoglobin level cut-off is slightly higher than what a healthcare provider may use to diagnose anemia. 

For whole blood the minimum hemoglobin level required is different based on donors’ gender at registration. Hemoglobin level requirement is 125g/L for donors registered as female and 130g/L for donors registered as male.      

Every person’s hemoglobin level is different. This is because there are many processes within the human body that impact hemoglobin levels. These include, and are not limited to, levels of sex-hormones that determine circulating testosterone levels or have impact on menstrual blood losses. Other factors include nutrition, altitude where people reside, other inherited conditions, etc. The gendered minimum hemoglobin level threshold is only an approximation to ensure there is sufficient time for blood level recovery from blood donation and for hemoglobin levels to be optimal for day-to-day functioning. 

After a plasma or platelet donation, hemoglobin levels do not fall drastically. The recovery from the smaller hemoglobin loss can occur quickly for all donors, so the minimum hemoglobin level required for all donors is the same at 125g/L. 

We check each donor’s hemoglobin level at the clinic before every donation with a finger stick test. Our devices use a very small amount of blood from fingertips and provide a result in real-time.

To ensure donors have sufficient blood levels after donation and to prevent anemia, a minimum hemoglobin level is required at each donation. This required hemoglobin level cut-off is slightly higher than what a healthcare provider may use to diagnose anemia.

When a donor does not meet the minimum hemoglobin level cut-off required for donation, they may not have anemia.

For instance, the threshold for plasma donation is 125g/L. If our donor’s testing shows a level of 124g/L, they do not meet the criteria to donate plasma. This doesn’t necessarily mean they have low hemoglobin or anemia.

When people donate whole blood, red cells that have hemoglobin and iron are removed.

Each whole blood donation reduces hemoglobin levels by approximately 10 g/L and reduces the body’s iron stores.

Donors produce new blood to replenish the donation. Iron is an essential building block of blood. If your iron levels are low, your body may have more difficulty replenishing blood, hemoglobin does not return to prior levels and lower hemoglobin and anemia can develop.

We recommend that you see your healthcare provider to check your hemoglobin and iron stores (ferritin). Your healthcare provider will investigate reasons why your hemoglobin may be low and may suggest taking iron supplementation.

Being deferred for low hemoglobin protects your own health. Most people who have low hemoglobin recover and return to donate.

It can take four to six months to replenish iron stores. If your healthcare practitioner has started you on iron pills, you may return to donate six months after starting them, provided your hemoglobin and iron levels have recovered. If you plan to donate regularly, speak to your healthcare provider about taking iron supplementation to prevent low iron levels.

Consider limiting how often you donate blood to two to three times a year.

Yes.

High hemoglobin, also called polycythemia, can occur. Some causes of high hemoglobin (polycythemia) include smoking, testosterone supplementation, lung problems, kidney problems and problems in how the bone marrow makes blood (blood cancers).

Some of the causes of high hemoglobin are also a cause for donor deferral, either for donor wellbeing or recipient safety. Therefore, additional information may be required from the donor’s healthcare practitioner to determine eligibility.

We understand that this can be frustrating. Here are some things you could do:

• Try to increase iron-rich foods in your diet
• Reduce your blood donation frequency
• Speak to your healthcare practitioner about hemoglobin testing, iron level (ferritin) testing and iron supplementation.

Anemia is the medical term used when an individual has low hemoglobin.

Every person has a different personalized range of hemoglobin.

To appropriately test for anemia, it is important to consult with your healthcare practitioner. Low hemoglobin or anemia occurs for many different reasons. Iron deficiency is the most common cause of anemia. Other causes include vitamin B12 deficiency, blood breakdown (hemolysis), altered function of vital organs, various types of cancers, etc. As donation leads to removal of blood it can cause and worsen anemia.

Anemia can lead to symptoms such as fatigue, difficulty breathing, lowered exercise tolerance, light-headedness and difficulty concentrating.

If you have anemia, please return to donate once the cause of anemia has been treated and hemoglobin improves.  

When people donate whole blood, red cells that have hemoglobin and iron are removed.  

Each whole blood donation reduces hemoglobin levels by approximately 10 g/L and reduces the body’s iron stores.  

Donors produce new blood to replenish the donation. Iron is an essential building block of blood. If your iron levels are low, your body may have more difficulty replenishing blood, hemoglobin does not return to prior levels and anemia can develop.  

Anemia from blood donation usually occurs due to depletion of the iron stores. All donors should consider iron supplements under medical supervision to help replenish their iron stores.

We recommend that you see your healthcare provider to check your hemoglobin and iron stores (ferritin). Your healthcare provider will investigate reasons why your hemoglobin may be low and may suggest taking iron supplementation.

Iron requirements change with age and changes in body functions. Requirements are higher:

• For blood donors to help replenish donated blood
• During puberty
• For those who menstruate to replenish iron stores and restore blood levels
• while pregnant to ensure brain and blood development of the fetus
• while lactating (breast/chestfeeding) to meet the needs of the baby
• For those who are consuming a low iron diet

Iron stores in the body can be estimated by measuring ferritin levels. Low ferritin levels imply depletion of iron stores. High ferritin levels can occur for multiple reasons, including due to a condition called hemochromatosis.  

Other tests can also be used to assess iron levels and these are performed under the supervision of a healthcare professional.  

Fingerstick testing performed at the time of donation assesses hemoglobin levels. Hemoglobin levels can be normal even if the iron stores are low.  

Iron comes in two forms:  

• Heme iron - which is more easily absorbed by the body and found in foods with heme iron. For example: beef, lamb, pork, liver, veal, chicken, turkey (the dark meat has more iron), fish and seafood.
• Non-heme iron - which is less easily absorbed by the body and found in foods with non-heme iron. For example: breakfast cereals (fortified with iron), breads and pasta (whole grain and enriched), lentils, dried peas and beans, tofu, seeds and nuts (pumpkin, sesame or peanut), dried fruit (raisins or apricots), dark green, leafy vegetables, and eggs.

People who have a low iron diet, drink tea or coffee with meals, may not be getting sufficient iron from diet alone. 

If you think your iron is low, please see your healthcare professional to determine if you need any tests done and advise about iron supplements.

If you donate blood, you may require iron supplementation in addition to the iron in their regular diet to help replenish iron stores and prevent anemia (low hemoglobin).

Individuals who have been diagnosed with hemochromatosis are not recommended additional iron supplementation.

We suggest you discuss taking iron supplements with your healthcare provider.

Yes. Hemochromatosis is an inherited condition where too much iron is absorbed from the diet and stored in the body. Eventually, the excess iron accumulates in tissues and can compromise the function of vital organs such as the liver, pancreas and heart.

Hemochromatosis is an inherited condition that leads to too much iron in the body. Eventually, the excess iron can compromise the function of vital organs such as the liver, pancreas and heart.

Often, hemochromatosis is identified before vital organ function is affected. Those with preserved organ function and hemochromatosis are eligible to donate, provided they meet all the other donation criteria.

Treatment of hemochromatosis usually includes reducing iron intake and removing excess iron from the body.

People with hemochromatosis reduce iron intake by avoiding iron-rich foods, as well as multivitamins with iron or iron supplements.

Removal of blood, called phlebotomy, is the main way to decrease iron levels and prevent iron accumulation. Phlebotomies for treatment purposes are performed under the supervision of a prescribing health practitioner at medical facilities.

People with hemochromatosis can donate blood, provided they meet all Canadian Blood Services donor criteria. Donor criteria includes an extensive medical eligibility questionnaire as well as wellness check at the collection centre.

Donor eligibility screening helps ensure that the phlebotomy will not harm the donor, nor impact the safety of the blood product or the safety of recipient. For this reason, people with complications of organ dysfunction are not eligible to donate. Many people have improvement of organ function after regular phlebotomies. It is possible that even if not initially eligible to donate, those who have recovery of their organ function can subsequently become eligible to donate whole blood.

All whole blood donors, including those with hemochromatosis, can donate blood every 56 days if they are registered as male and every 84 days if they are registered as female.  

Individuals may have phlebotomies in between donations, providing there is at least a 1-week gap. between an outpatient phlebotomy and their next Canadian Blood Services donation.