Each year, Canadian Blood Services (CBS) collects about 950,000 units of blood from approximately 600,000 donors. That’s a lot of blood, and a lot of lives that can be saved because of it! Did you know that a single donation can save up to 3 lives?
While donating blood is an extremely generous act to help others who are in need, it is also important to take care of yourself in the process. The Dietary Reference Intakes note that one blood donation (500 mL) just once a year translates into an additional iron loss of about 0.6 mg/day throughout the year. When we consider the amount of iron that is lost with each blood donation, and that 90% of donations come from repeat donors, it is important to discuss iron deficiency and the need to replenish your iron after donating.
Why Are Blood Donors At Risk?
Iron deficiency is more common in blood donors, particularly those who donate frequently and those who are female. According to a recent report regarding Iron Status in Canadian Blood Services Donors (June 2014), on average, repeat donors give blood twice per year. For every donation (500 mL each), a person loses 225 mg – 250 mg of iron. Since women are already at greater risk for developing iron deficiency (mainly due to menstruation and pregnancy), the risk in female donors is even higher.
This is in no way meant to scare you and put you off donating blood. Whether you are a frequent donor or a first-time donor, most people don’t realize that their need for iron increases when they donate blood and don’t think to speak to their doctor about it. Part of this also has to do with the misconception that if you pass your donor screening test, then your blood must be fine. Unfortunately that’s not the case; passing means that your hemoglobin level is okay, it doesn’t mean that your iron stores are up to snuff. Being aware of this, preventing iron deficiency can keep you healthy so that you can continue to be your generous, blood-donating (and life-saving) self!
“I Went to Donate Blood, But I Was Deferred”
Hemoglobin is checked before each donation using a drop of blood from the finger. Some people discover that they may be anemic when they arrive to donate blood and fail the hemoglobin screening (minimum qualifying level of 125 g/L for both males and females). As noted in the CBS report, 8% of female donors and less than 1% of male donors are temporarily deferred for inadequate hemoglobin level, and almost all donors who fail this screening are found to be iron deficient.
If you wish to donate blood but are deferred, CBS provides individuals with an information sheet (see page 9 of the report), advising that a visit to the doctor is in order to determine the cause of your low hemoglobin level (and you cannot return to donate blood until doing so).
Replenishing Your Iron after a Blood Donation
Studies have found that supplementing a total of 2000 mg – 4000 mg of elemental iron (over time) will replace the iron lost from one blood donation (see chart below). Though eating more foods rich in iron is generally a good idea, this may not be enough to replenish your iron and rebuild your iron stores; in many cases, using an oral iron supplement will aid in reaching the desired level faster.
CBS provides a chart which outlines various iron supplementation options to replace one whole blood donation, including available iron preparations, the relative amount of elemental iron, and how many tablets it would take to replenish the iron lost from one donation.
Iron Supplementation Necessary to Replace One Whole Blood Donation*
| Iron Preparation | Tablet (mg) | % of Elemental Iron | Elemental Iron Content per Tablet | #Tablets for 2000 mg Total Dose | # Tablets for 4000 mg Total Dose | Recommended Daily Dosing** |
|---|---|---|---|---|---|---|
| Ferrous sulfate | 300 mg | 20% | 60 mg | 33 | 55 | 1 tablet 2-3 times a day |
| Ferrous gluconate | 300 mg | 11.6% | 35 mg | 57 | 114 | 1-3 tablets 2-3 times a day |
| Ferrous fumarate | 300 mg | 33% | 99 mg | 20 | 40 | 1 tablet 2-3 times a day |
| Polysaccharide-iron complex | 150 mg | 100% | 150 mg | 14 | 28 | 1 capsule once per day |
* Mindy Goldman. “Iron Status in Canadian Blood Services Donors.” Canadian Blood Services. June 2014
**Recommended daily dosing derived from: Anemia Guidelines for Family Medicine, 3rd Edition, 2014 (page 11)
For donors who have been directed by their doctor to take an iron supplement for their iron deficiency anemia, CBS advises them to complete 6 months of therapy (and resolve the iron deficiency anemia) before returning to donate blood.
Understanding that people who frequently donate blood have higher iron requirements is important. Whether you have donated blood, regularly donate, or are thinking about doing so, you may like to consider replacing the iron you have lost using an oral iron supplement.
For those of you who donate, thank you! And for those of you wanting to donate, take a few minutes to fill out the Canadian Blood Services eligibility quiz to get started!
Content and advice provided on The Iron Maiden is for information purposes only and should not serve as a substitute for a licensed health care provider, who is knowledgeable about an individual’s unique health care needs
