When you give blood . . . .

[Karen]

It is iron they test for, not hemoglobin. They only take a pint of blood from you - that's 2 cups, not three.

And every woman's body is different, some women lose a lot of iron around their menstrual cycle, others it has little to no effect. A lot depends on your diet, I for example, cannot eat most red meat because of allergies, so I have to stay healthy by making sure I get enough iron other ways.

[pomtzu]

It is iron they test for, not hemoglobin.

They go hand in hand. If iron is low, hemoglobin will be low.

[tokolosh]

It is iron they test for, not hemoglobin. They only take a pint of blood from you - that's 2 cups, not three.

And every woman's body is different, some women lose a lot of iron around their menstrual cycle, others it has little to no effect. A lot depends on your diet, I for example, cannot eat most red meat because of allergies, so I have to stay healthy by making sure I get enough iron other ways.

I know everyone's body is different and replenishment depends partly on diet and other factors. I wasn't wondering about that so much, just how much iron is there in a bag of blood, because once it's in the bag it isn't in ME anymore. Even allowing for varying count levels to start with, you could work out a ballpark idea of how much your score might drop right afterwards by playing with the proportions concept. I'm simply curious.

But I just called the Red Cross to find out, and it seems they don't know either At least the woman I asked was very surprised by the question and said she'd never thought about that before. Guess I'll just have to stay curious, or march back in and ask them to prick my finger again to satisfy my curiosity. Either way, it's a good excuse to eat clams.

You were right that it's iron they check, according to her. But then I found this statement which seems to confuse things again "Iron status is also noted by measuring hemoglobin and hematocrit levels; this is because iron is a major part of all blood cells. Blood levels of hemoglobin and hematocrit are often checked by a skin prick", which is how they do it up here.