How can I build up my blood hemoglobin level?

Q. I donate blood about four times per year. My most recent blood count was a bit low. The blood bank told me to wait another month. What can I do to build up my blood?

A. It's terrific that you are a regular blood donor! Each time you give blood, the technician will first check your hemoglobin level. It must be at least 12.5 grams per deciliter before you can donate.

Hemoglobin is made up of iron and protein. It is the part of red blood cells that carries oxygen throughout the body. To keep hemoglobin levels normal, you need to have enough iron in your body.

When you donate a pint of blood, you lose about 230 milligrams of iron. Your small intestine responds to the loss of iron by absorbing more iron from your foods than usual.

But it takes two to three months (and sometimes longer) to regain all the iron stores. Most likely your intestines did not have enough time to absorb enough iron to get you to the 12.5 hemoglobin level.

Taking an iron supplement, such as 325 mg of ferrous sulfate or ferrous gluconate, can help boost hemoglobin levels faster after blood donation. It's best to take only one dose daily, or even just one dose every other day.

Ferrous sulfate has more elemental iron than the gluconate preparation. However, ferrous sulfate is more likely to cause an upset stomach and constipation.

If you do experience nausea or stomach upset, it's fine to take your pills with food. But don't take them with milk, antacids, or calcium, as these block absorption.

Don't be alarmed if your stool gets very dark. It's from the iron.

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