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Overhead view of an assortment of colorful foods.
Overhead view of an assortment of colorful foods.

What Should I Eat Before Donating Blood?

Prepare Your Body

Donating blood is an extremely rewarding experience that offers the opportunity to save more than one life with just one donation. People sometimes feel dizzy or weak after giving blood. Don’t let this prevent you from making a difference. With proper nutrition and hydration beforehand, you’ll avoid some of these uneasy feelings.

Since your body is made mostly of water, it’s important to stay hydrated before (and after) giving blood. A loss of fluids can lead to a drop in your blood pressure, which explains why some people may feel dizzy.

“Blood transfusions are so important for our patients. We want our blood donors to not only feel good about their experience, but also to feel well afterward,” says Glenn E. Ramsey, MD, medical director of the Blood Bank at Northwestern Memorial Hospital and professor of Pathology at Northwestern University Feinberg School of Medicine.

Before you donate blood, Dr. Ramsey suggests you should eat foods that are rich with:

  • Iron. The removal of red blood cells depletes iron stores from your body, which can take about eight weeks to replace. If you don’t have enough iron stored away prior to giving blood, you could become anemic, which can make you feel tired and weak. Iron-rich foods include red meat, eggs, poultry, fish and leafy green vegetables.
  • Vitamin C. In contrast, vitamin C helps your body absorb more iron, which can help your body replenish itself and avoid iron deficiency. Reach for citrus fruits, pineapples, mangoes or Brussels sprouts.

After you donate blood, the blood donation team members usually offer light refreshments to help your body replenish the nutrients you’ve lost. It’s important to eat something, as your body needs to regain energy to rebuild lost cells. You should also avoid too much caffeine, as it can lead to dehydration and exhaustion. Continue to stay hydrated and avoid alcohol for at least 24 hours.

Learn how to become a blood donor at a Northwestern Medicine location near you.