I wrote about iron deficiency in athletes more than a year ago, so it’s definitely time for an update. Especially because I consider myself newly in the “mildly iron deficient” category (shaking my head as I write this), which I will get into.

But first, a ferritin refresher
Ferritin is a protein in the blood that stores iron, and when low, is the first sign that you are iron deficient. Hemoglobin, a protein in the red blood cells that carries oxygen throughout the body, can be normal when your ferritin is low. If both your ferritin and hemoglobin are low, you are considered to be iron deficient with anemia. Having ferritin checked regularly is a very helpful tool in catching iron deficiency quickly so it can be treated before becoming anemia and having more detrimental effects on performance, though low ferritin alone can also impact performance and how you feel physically. Ferritin is not something that is typically ordered on routine labs, so asking your doctor to add it is usually necessary.

burger with lettuce and tomato — Photo by Food Photographer on Unsplash

Ok, what should my numbers be?
Here’s where things get a little tricky. For women, a ferritin of more than ~15-20 considered normal. However, for female athletes, especially those in endurance sports, ferritin should be above 30 at minimum and can impact performance if it falls below 30. This is not widely understood, with my recent experience being the perfect example. During a routine physical a few weeks ago, I had my PCP add ferritin to my labs. When the results came back, my ferritin was 22 and she said it was normal and fine. Not fine for me though, since I would still put myself in the “endurance athlete” category.

Ferritin goals are not one size fits all
The other complicating factor is that, other than aiming for above 30-40, there is no one size fits all ferritin goal for female athletes (and this is based on my PubMed deep dives and discussions with colleagues). Here is when we have to take the individual into account. Athlete A may have a consistent ferritin of 45 over the last couple of years, be crushing her workouts and meeting her energy needs. I would say this is likely an ok ferritin for her. Athlete B may have had a ferritin of 70 last year, but started training more heavily in the past six months, is feeling tanked during easy runs and now her ferritin is 40. I would say this may not be an adequate ferritin for her - her iron needs likely increased with the intensity of her training and weren’t being met, as evidenced by the downward trend and how she feels. Athlete C has had her ferritin checked for the first time and it’s at 14. Her race times have plateaued, she’s struggling to eat enough to support her training, and has had some disordered eating in the past. I would say universally, this is too low a ferritin and lots of factors need to be addressed in order to correct it and find her ferritin “happy place.”

Trends are crucial
When interpreting lab values, it’s really important to look at the trends to understand what’s normal for the individual. As outlined above, a ferritin of 45 could be ok for one athlete, and inadequate for another based on what the numbers have historically looked like. It’s hard to really know what’s going on when just seeing one number in isolation, with the exception of the Athlete C example above.

Which brings me back to…me
I always recommend my athlete clients have ferritin checked at least a few times per year, moreso if their training intensity increases, they aren’t feeling great, they change their diet, or if they’re at altitude for prolonged periods. I, however, haven’t had my ferritin tested in quite some time, and I couldn’t even tell you specific trends for me. I feel ridiculous just typing that! So I’ve got nothing really to compare my numbers to, but think my ferritin could definitely be higher and runs could probably feel better. The treatment plan I developed for myself includes a slow release iron supplement, more iron rich foods, a little less running (which I will talk more about in another post), and another ferritin check in a couple months. Hold me accountable, internet.

Quick notes on iron supplementation
Iron supplementation is best when recommended by a professional and when labs can be monitored. It’s possible to experience iron overload, which some individuals are more sensitive to than others, and can be dangerous. Supplementation may also not be beneficial once ferritin levels exceed 60-70.

Low energy availability and iron status
It can’t go unsaid here how important it is to consume iron-rich foods on a regular basis (I have a list of them in my other post, linked above). However, if an athlete is not meeting energy needs, it is highly likely they’re also not meeting iron needs. Eating enough can likely have a positive impact on iron levels in these cases.

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Nutrition, etc.

Do as I say, not as I do: a ferritin…