Blood donations result in a loss of red blood cells and the iron they contain.
A significant loss of red blood cells can lead to a decrease in the capacity of the blood to transport oxygen; this is called anemia.
Before each blood donation, we make sure that you have enough red blood cells to give blood without any risk of becoming anemic; this is the hemoglobin test.
After a blood donation, the body replaces the red blood cells lost.
The bone marrow regenerates these red blood cells. It takes about one month for the red blood cells to return to the level prior to the donation.
To manufacture new red blood cells, the bone marrow must use the iron it takes from the individual’s iron reserve. The individual must then rebuild his/her iron reserve.
The iron needed to compensate for the losses and maintain the iron reserve at an adequate level comes from food and is absorbed by the intestine.
In the case of people making frequent blood donations (three or more whole blood donations – or more than one double red cell donation - per year for men, two or more whole blood donations for women), the iron absorbed from food cannot compensate on its own for the iron lost through the donations. In most cases, donating plasma does not result in loss of iron. However, in the case of frequent plasma donors, taking the blood samples required for each donation may cause a loss of iron.
In the case of women who have not yet gone through menopause, the monthly loss of menstrual blood means their iron reserves are lower than those of men. Therefore, women are more likely than men to experience a significant decrease in the iron reserve.
A decrease in the iron reserve can result in a sensation of fatigue, a decreased capacity for exercise, difficulties concentrating or even pica (a dietary problem characterized by the ingestion of non-nutritional substances such as ice or chalk). A sufficiently low reserve can result in anemia, which causes the same symptoms but to a more severe degree.
Is the iron reserve measured during a blood donation? No, except in the case of certain double red cell donors. The test we perform on all donors before the donation measures the level of hemoglobin in the blood. To measure the iron reserve another test, called a ferritin test, is performed.
How can you maintain the iron reserve at an acceptable level?
First, eat a diet that is rich in iron. The foods that are richest in iron include variety meats (liver, kidney) and red meat. Oysters are also rich in iron. White meat, fish, seafood, legumes and enriched cereals are also good sources of iron. The iron that binds with heme, a molecule that is contained in hemoglobin and found in foods of animal origin, is absorbed better than iron of vegetable origin and is not influenced by diet. Vitamin C promotes the absorption of non-hemic blood, whereas the tannins contained in tea and the phytates found in certain vegetables hamper absorption.
In the case of frequent donors, andparticularly women, the iron content of food can be complemented by iron supplements available at the drug store. If you are a frequent donor, talk to your doctor or pharmacist. The optimal dosage for compensating for iron losses resulting from blood donations may vary; however, a dosage of elemental iron ranging from 19 to 45 mg per day, for 6 to 12 weeks after a donation, may be sufficient.