Iron Information for Blood Donors

We do not directly measure your iron. You get a mini-health exam when you come in to donate, and we prick your finger to test your hematocrit level. Blood has three components—red blood cells, plasma and platelets. The hematocrit test measures red blood cells because iron increases them.

You may need iron if your hematocrit is low, which happens late in iron deficiency. You can have low iron and still have a normal hematocrit level, but health problems from low iron are rare before the hematocrit falls.

Iron pills or multivitamins with iron can help. The pills work faster than foods with a lot of iron; 18-38 mg of iron once a day for eight weeks replaces iron lost during a donation. There are no more side effects than a sugar pill. You should talk to your doctor about your needs. Iron fuels your body for the next donation, and healthy donors save more lives. 

Donors most likely to need more iron:

Those who are growing:

• Pregnant women
• Teenagers and young adults

Adult donors must wait 56 days between whole blood donations.

Our young donors must wait longer:

• 16-18-year-old males — 84 days
• 16-18-year-old females — 112 days

Donors with a hematocrit level near or below the minimum required:

• 38% for women
• 39% for men

Frequent donors:

• Women, ages 16-50, who give more than one whole blood/red cell donation a year
• Men and women over 50 who give more than two whole blood/red cell donations a year
• Platelet donors who give more than once a month

If you are a frequent donor or are at risk for having low iron stores, taking an iron supplement is highly recommended. Talk to your health care provider to decide if iron is best for your health.