Tracking ferritin after blood donations

My last two blood tests flagged ferritin as low, and total iron as high. I don’t have anemia, and related markers like hemoglobin are all fine.

This is likely due to regular blood donations (after having done none for several years). Everything I had read indicated that 4-6 weeks should be plenty to recover, and while this may be true for red blood cell counts and hemoglobin, maybe not for ferritin.

Low ferritin in itself doesn’t appear to be harmful, but rather than risk developing anemia, I’ll reduce the donation frequency from 3 to 6 months, and retest iron-related biomarkers prior to the next donation.


Vertical lines mark blood donations (500ml whole blood). The grayish areas are the “reference” ranges.


Source code here.

Looks like “total” iron has come back down to earth, and ferritin is slowly creeping up again. Serum iron levels are known to vary a lot, so I don’t know if I can blame the blood donations for upsetting the total iron values, or maybe I just ate more red meat in the days prior to the last test…

I’ll hold off a couple more months before doing another donation, and then stick with one donation every 6 months.


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Although ferritin is an acute phase reactant (meaning it rises during acute illness or inflammation), when not ill, it is a better measure of total body iron stores.

If you want to donate more, pick up over the counter ferrous sulfate 324 mg (65 mg iron) and take one pill 3 times per week. The two side effects are darker stools and constipation which is why I recommend 3 times per week. When people are iron deficient due to chronic blood loss, we recommend taking it daily with a stool softener. However, for your purposes, three times per week should do. You can titrate the dose according to your donation schedule.


I’m just going to adjust my donation schedule according to my natural recovery rate, not vice versa :grinning:

I do still wonder why my “total iron” levels were elevated about two months post-donation…

Looks like my ferritin levels are back in the normal range. Planning to donate blood later this week, and will stick with twice-a-year (rather than quarterly) donations from here on.


Thought it would be interesting to use this app to see if a blood donation resulted in a measurable reduction in hemoglobin, and how many days it would take to get back to normal. Unfortunately the readings fluctuate ±1 g/dL – and the expected reduction after donating is only 1 g/dL.

Interestingly, there was also a discrepancy between the hemoglobin reported in a recent lab test (15.1 g/dL) and the fingerstick test they do prior to donating (16.4 g/dL). Turns out this is a known issue.

In any case the “collection specialists” somehow managed to miss-tap my immaculate veins twice in a row, so this experiment will have to wait for another time :upside_down_face:

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Turns out that there is evidence that iron deficiency even in the absence of anemia negatively impacts exercise metrics.

Hadn’t noticed this myself, but then again I wasn’t doing controlled stress tests, so I’m not sure I would have noticed a 10% reduction in maximal aerobic capacity…

*Loss of Aerobic Capacity after Blood Donation *

Eric, I experienced this first hand about 10-12 years ago. I donated blood and found I could not keep up my Wednesday night running group. The coach, who had a PhD in Immunology, just laughed at me and said: “Don’t you know the literature on this topic? “. It’s basically the reverse of blood doping. I slowly regained my performance over 4 to 6 weeks.

Even in amateur sports, many of us suspect all different types of doping is going on. Not much testing even in world champ races. Most if not all the Doping methods carry risks that are not worth it besides the fact it is cheating.

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