Ferritin is a protein that binds with iron and keeps it available for use, if I understand it correctly. It's one measure of stored iron in your body, basically.
Online, ferritin levels considered "normal" vary from source to source. The lab I used listed 11-307 as "normal." Medline Plus lists normal ferritin levels as:
Male: 12-300 ng/mLMost online sources I've read state that while "normal" may be as low as 12, people should start getting concerned with levels below about 50.
Female: 12-150 ng/mL
"The lower the ferritin level, even within the "normal" range, the more likely it is that the patient does not have enough iron."
Guess what my level was? 7.2. Definitely below any measure of "normal" and basically in the toilet. Great.
Now, my hemoglobin and hematocrit are in the "normal" range.....but only just barely. My hemoglobin was 11.6 and the cutoff is 11.5; my hematocrit was 35.4 and the cutoff is 34.7 at my lab. So not "officially" anemic, but barely above the cutoffs. And the ferritin is definitely abnormally low (7.2 when it should be at least 11).
The good news is that we had other levels tested last year to figure out which kind of anemia I had. My folate levels are good (I have aggressively supplemented these over the years because of pregnancy and breastfeeding) and my B12 levels are also good. So with the really low ferritin levels, it looks like it's iron deficiency anemia.
I've been struggling with this for a while. I've often been a bit borderline anemic over the years, but not enough to cause big problems. In pregnancy, I used "Floradix" - an herbal over-the-counter preparation - and that helped immensely without causing constipation, the way that iron pills can. It's great stuff, much better than OTC iron. It's what got my hemotocrit and hemoglobin levels up this past year.....but apparently it doesn't have as much effect on ferritin levels. Bummer.
As I've gotten older, I've had more issues with anemia, enough so that I was no longer able to donate blood to the Red Cross anymore. I'm a fairly rare blood type so they love me, but I haven't been able to donate now in several years because of the anemia. In fact, my donations probably exacerbated my low iron issues.....but I haven't donated in several years now, and my ferritin levels are still down to 7.2, so obviously it's much more than just blood donation going on.
Part of the problem is being perimenopausal. One symptom of impending menopause you don't hear a lot about is extremely heavy periods, called "menorrhagia." Colloquially, it's called the "blood flood" and sadly, it's very aptly named.
My periods were always reasonably normal, not usually too heavy or too painful. I skipped months periodically because of the PCOS, but once my hypothyroidism was finally diagnosed and treated, I never skipped a period again. (Still have other PCOS symptoms but as long as they hypothyroidism is treated, they stay relatively mild. Now, with my TSH going up, they're starting to act up more again. Ugh.)
As I've become perimenopausal, the periods became heavier and heavier. So this is quite likely a big cause of the low ferritin levels too. But I'm happy to report that as I move closer to menopause (and with the help of acupuncture), the heavy periods have eased up, thank goodness! And yet, despite this, my ferritin levels are still at an all-time low. So obviously, menorrhagia is not the only cause for my low ferritin levels.
I eat plenty of iron foods, I cook in iron skillets, I regularly take vitamin C with my iron, I avoid calcium etc. with the iron, I eat plenty of red meat (a more easily absorbed source of iron), and basically do all the things that are supposed to "fix" this problem. And none of them are working.
What I learned recently, though, is that hypothyroidism and anemia tend to go hand in hand. When you have one, you often have the other, especially if there are any other challenges to your system (like pregnancy, birth, blood donation, heavy periods, etc.).
And apparently, undertreated hypothyroidism in particular tends to result in low ferritin levels.
So it will be interesting to see whether getting my TSH levels back to where they feel better to me will also coincide with an improvement in my ferritin levels. I am also taking supplemental iron and Floradix. Hopefully all of that will be enough to get things back to normal. Keep your fingers crossed!
[Anyone else with hypothyroidism had problems with anemia and low ferritin in particular? I'd love to hear about other people's experiences and what helped you.]