Iron: a Primer for the Vegan Female Athlete

By: Pamela Fergusson, RD, PhD

There’s an all too familiar story of a female runner who breaks into running, trains hard, and starts racking up Personal Records. She grows to love running, and running seems to love her right back.

But with time, her energy wanes, training slips, and paces taper off.

No matter how she adjusts her training, she’s left feeling more tired and worn down with each run.

The culprit? It could be an iron deficiency.

As a nutrition consultant, registered dietitian, and avid ultrarunner, I see this all the time with my friends and clients. Low iron levels can have a drastic effect on both your training and general health.

But when it comes to iron for vegans, how much do you need? And how can you maintain appropriate levels?

Iron Deficiency and Women

While iron might not be as hot a topic as vegan protein or other vegan supplements, it’s actually the most common nutrition deficiency in the world (including in the USA).

Only two percent of adult men are iron deficient, but it increases to 9-12 percent of Caucasian women and nearly 20% of black and Hispanic women. Even in the general, non-runner, non-vegan population, there are a lot of people who are iron deficient, and female athletes may be at an even higher risk.

A 2011 study of female collegiate rowers in New York found that 30% of the athletes tested had low iron stores. Yup, nearly a third of all women in the study.

All that’s to say that iron deficiency is common among all women of childbearing age, and it’s probably even more common for athletes.

Why Female Athletes are at Risk for Anemia

You run, practice yoga, and eat plants. There’s nothing to worry about, right? Like it or not, there are a few situations when your healthy exercise habits may actually increase your risk of certain issues, and this is one of those times.

Female athletes are at a greater risk for iron deficiency because along with losing iron in blood monthly through menstruation, we also lose iron through sweat, and our iron absorption is reduced through exercise-induced acute inflammation.

There are other factors which could be of particular concern to runners, such as hemolysis (the rupturing of blood cells from a repeated foot strike), but there’s some controversy on the research so let’s skip it for now.

Then there’s the whole cycle of diminishing returns, which is far too common in runners and other athletes. When you’re no longer seeing the results you want, your instinct is usually to push harder, leading to even more fatigue and depletion of iron stores, instead of stepping back to give yourself the chance to fully recover between workouts.

And that’s a cycle nobody wants to get stuck in.

How to Know if You’re Deficient in Iron

If you’ve made it this far into a No Meat Athlete article, I’m willing to bet you already agree eating a whole foods plant-based diet is healthy and ideal. And that for the most part, all the hoopla around whether or not we get enough nutrients through plants is not of concern.

But research shows that while omnivores can also develop anemia, vegetarians or vegans may be at a slightly increased risk.

Now don’t panic — there’s nothing to freak out about. As a vegan, simply be on the lookout for the symptoms, like:

Tiredness or weakness
Pale skin
Headaches or lightheadedness
Declining athletic performance
Cold hands and feet
Hair loss
Loss of appetite
Cravings for ice, dirt, or clay

If you’re thinking any one of those (except for maybe the dirt cravings …) could be the sign of a dozen other things, then you’d be right. But that doesn’t mean you can ignore them.

Iron deficiency occurs when your stores of iron decline below normal levels, and anemia refers to low hemoglobin, the measure of iron circulating in the blood. When either of those take place, it will likely trigger one or more of the symptoms above.

And if that happens, do yourself a favor and talk to a doctor.

Side note: If you have very heavy periods, that’s also something to report. Large blood losses may make it difficult to avoid anemia.

A doctor will assess your iron levels by testing your hemoglobin — whether or not you have enough red blood cells (low levels make you anemic) — and your ferritin. Low ferritin levels indicate a deficiency in iron stores. The good news is, if your ferritin levels are low, your body will automatically start absorbing more iron from the foods you eat.

Doctors measure your levels through a simple blood test.

Your doctor can then determine if an iron deficiency is a sign of something more serious, like chronic infections, cancer, celiac disease, or uterine polyps (do I sound like a drug commercial yet?). But most likely it’s just a simple absorption problem.

Let’s take a step back to break down how iron absorption works, and how to prevent a deficiency from developing in the first place.

Understanding Iron Absorption

There are two types of iron: heme and non-heme iron.

Heme iron comes exclusively from animal source foods, and it’s more easily absorbed by our bodies than non-heme iron. Interestingly, however, only about 40% of the iron from animal-sourced foods is heme iron. The rest is non-heme, which comes from both animal sources and plants.

For the typical omnivore, only about 10% their iron is heme iron, because the majority of iron they consume actually comes from grains and veggies. All iron found in plant foods is non-heme, and while non-heme iron isn’t as easily absorbed, our bodies don’t need both non-heme and heme sources to thrive.

Bored yet? I bet this will get your attention:

Our absorption of non-heme iron can be further reduced by calcium intake and by compounds in soy, coffee, and tea.

In fact, a cup of coffee may reduce the iron we absorb by up to 39%, and a cup of tea by 64%. So after eating an iron-rich meal or taking an iron supplement, I recommend to wait two hours before enjoying coffee or tea.

That sounds worse than it is. You can avoid this issue altogether by keeping coffee and tea to break time instead of during a meal.

How to Increase Iron Intake and Prevent Iron Deficiency

Like any nutrition-related issue, the focus should first be on prevention — or in this case, increasing iron consumption and absorption before there’s a problem.

I like to start in the kitchen, since there are a ton of iron-rich plant-based foods we can easily consume on a daily basis, including:

Legumes — lentils, kidney beans, soybeans (tofu, tempeh), lima beans
Grains — barley, quinoa, buckwheat, fortified cereals, brown rice, oatmeal
Dried fruit — apricots, flaked coconut, dried prunes, dried pears, and sun-dried tomatoes
Nuts and seeds — cashews, almonds, macadamias, pumpkin, squash, pine, pistachio, sunflower
Vegetables — dark leafy greens like Swiss chard and collard greens, tomato sauce
Other — cocoa powder, blackstrap molasses, prune juice

Find recipes that incorporate several of these ingredients, like this Chickpea Tagine or Lentil Soup, or (and this is my favorite) simply combine many of the foods above into one giant iron-rich stir-fry with greens, legumes, and other veggies on top of a bed of quinoa.

Top it off with raw nuts and seeds for an extra punch (and crunch).

When it comes to absorption, it’s not just about what you eat, but how you eat it. As you prepare your food:

Pair iron-rich meals with a food source of vitamin C, which will increase the absorption of non-heme iron. It’s super easy to do, as many iron-rich and vitamin C-rich foods go together (think hummus made with lemon juice or black beans with lime and red peppers).
Cook in cast-iron cookware, especially if you’re making an acidic food like tomato sauce. A small amount of iron will always leach from the pan into your food, but acidic foods enhance this process — that is a good thing!

But, of course, there are times when iron levels drop below normal, no matter what sort of prevention measures you’ve taken in the kitchen.

Iron Supplements

If you become iron deficient, increasing iron intake through food might not be enough to get you back on track, and a supplement may be needed.

If you do take an iron supplement:

Take it with food so you don’t upset your stomach.
Consider taking a vitamin C supplement along with it to increase absorption.
Don’t take a calcium supplement at the same time (spread them out throughout the day).
Avoid taking it directly after a hard workout, when absorption may be reduced.
Avoid coffee and tea within two hours of taking the supplement, or better, avoid them all together.

There’s absolutely nothing wrong with taking supplements when you need them, but when you do, take them in a way that allows for the best absorption rate.

Iron is Your Friend, Don’t Neglect It

Looking after our iron stores is an important part of maintaining our health and performance as plant-based female athletes. Since anemia is such a widespread issue, it’s one area of nutrition that I always recommend you attack preemptively, before it becomes a problem.

Many of us can do that on a whole foods, plant-based diet and a well-planned training regimen. But for some, extra care through supplementation is needed.

Whether that’s you or not, all female athletes should take iron seriously, and if a symptom or issue is to ever arise, don’t hesitate to get it checked out.

Maintaining proper iron levels is one of the best ways to ensure that you get the most out of your training.

About the Author: Pamela Fergusson is a vegan Registered Dietitian with a PhD in nutrition. She and her husband Dave have four children, and she loves to speedwalk ultramarathons. Read her nutrition blog and find her on Facebook.