I still remember sitting on the couch at night, chewing ice.
There are not a few cubes here and there. Whole bowls of ice.
At the time, I was in my 20s. I ate a plant-based diet, worked out regularly, started running, and did everything I thought I needed to do for my health. However, I was exhausted the whole time. I couldn’t stay awake past 9pm. My legs hurt at night. My workouts were harder than they should have been.
I mentioned it on a busy schedule.
What I didn’t realize was that these were signs of severe iron deficiency anemia.
Years later, as a sports nutritionist working with runners, I’ve seen the same pattern repeat itself over and over again, especially among plant-based athletes and runners. Many assume that their fatigue is just part of training. Others think they are out of shape.
In fact, low iron was the culprit.
Because I am more prone to iron deficiency
My situation is a bit unique because I have thalassemia trait, an inherited blood disorder that affects hemoglobin production.
Hemoglobin is the protein in red blood cells that is responsible for carrying oxygen throughout the body. Because my body naturally produces less hemoglobin than average, I have spent most of my life monitoring my iron status.
As a child, I managed my iron levels through diet. But once I became a runner, things changed.
Running increases your body’s demand for oxygen and increases the rate at which you lose iron. Iron losses occur through sweat, urine and even the breakdown of red blood cells when your feet hit the pavement. This means iron becomes even more important for runners.
While the thalassemia trait increases my personal risk, I have learned that iron deficiency is incredibly common among most runners, even those without underlying conditions.
Signs of iron deficiency in runners
Iron deficiency symptoms may be subtle at first. They also mimic symptoms that many people feel on a daily basis, such as headache or fatigue.
Some of the more common signs include:
- Persistent fatigue
- Reduced running performance
- Difficulty recovering from workouts
- Feeling cold often
- Shortness of breath during exercise
- Hair loss
- Restless legs
- Headaches
- Pale skin
One symptom that surprised me was PICA, which is a craving for non-food. For me, this manifested as a strong desire to chew ice every night. Some people testing PICA eat dirt, clay, or other non-food items.
At the time, I had no idea that ice cravings could be associated with iron deficiency. Looking back, it was one of the biggest red flags.
Why runners are at higher risk for low iron
Iron plays a critical role in transporting oxygen throughout the body. Without enough iron, your muscles don’t get the oxygen they need to work efficiently.
For runners, several factors can increase iron losses:
1. Menstruation
Athletes lose iron every month through menstrual blood loss.
2. Sweat losses
Small amounts of iron are lost through sweat, which can be added during heavy exercise.
Every time your foot hits the ground while running, some red blood cells are destroyed.
This process, known as foot strike hemolysis, is another contributing factor to iron losses in endurance athletes.
4. Increased Education Requirements
Higher training volume increases the body’s need for oxygen transport, placing greater demands on iron stores.
Are plant-based runners more likely to be iron deficient?
The answer is yes, but no because plant-based diets are inherently deficient in iron.
Plant foods contain iron. In fact, many plant foods are excellent sources. The challenge is that plant foods contain non-heme iron, which is not absorbed as efficiently as the heme iron found in animal foods.
This means that plant-based athletes need to be more careful about their iron intake. Research shows that vegetarians and vegans may need up to 1.8 times more dietary iron than omnivores because of these absorption differences.
This does not mean that a plant-based diet causes iron deficiency. It just means you need a strategy.
Best plant sources of iron for runners
Some of my favorite iron-rich plant foods include:
- Lentil
- Beans
- Tofu
- Tempeh
- Edamame
- Pumpkin seeds
- Hemp seeds
- Quinoa
- Cereals fortified with iron
- Soy foods
These foods can absolutely support healthy iron levels when included consistently.
The iron absorption trick every runner should know
If there’s one nutritional strategy I wish more athletes knew, it’s this:
Combine iron-rich foods with vitamin C. Vitamin C greatly improves iron absorption. Below are some ways to do this effectively.
Combinations of iron + vitamin C
- Oatmeal + strawberries
- Lentils + tomatoes
- Tofu stir fry + peppers
- Black beans + salsa
- Pumpkin seeds + orange slices
When I was prescribed iron supplements, my doctor specifically told me to take them with vitamin C to improve absorption. The same principle applies to food.
Foods that can affect iron absorption
There are also foods and drinks that can reduce iron absorption.
Calcium
Large amounts of calcium taken with iron-rich meals may interfere with absorption.
Examples include:
- Milk
- Yoghurt
- Cheese
- Calcium supplements
Coffee and tea
Coffee and tea contain compounds that can block iron absorption.
If you take an iron supplement, avoid taking it with your morning coffee.
Personally, I take iron before bed when I’m not consuming caffeine.
When diet is not enough
One of the biggest misconceptions I hear is that severe iron deficiency can always be corrected through food alone. Unfortunately, this is often not the case.
When my ferritin level dropped to 2 ng/mL, dietary changes weren’t enough. I needed iron supplementation under medical supervision.
If you suspect low iron, do not self-diagnose. Ask your healthcare provider about blood work, including ferritin levels, which measure your iron stores.
Iron supplements can be incredibly effective when needed, but taking iron without medical guidance is not recommended because excess iron can also be harmful.
What I wish I had known earlier
Looking back, I wish I had heeded the warning signs sooner. I wish I had recognized that the constant exhaustion was not normal. I wish I knew that feeling slower on my runs didn’t automatically mean I was out of shape.
Most importantly, I wish I had understood that iron deficiency wasn’t a sign that my plant-based diet was failing. It was simply a matter of nutrition that required attention and management.
Today I still run. I still eat a plant based diet. And I still monitor my iron levels closely. For me, iron management is not perfection.
It’s a matter of awareness. Because when your iron levels are right, you feel the difference—not just in running, but in every part of your life.
The bottom line
Iron deficiency is one of the most common nutritional issues I see among runners, especially female athletes and plant-based athletes. The good news is that it’s manageable.
Know the symptoms. Prioritize foods rich in iron. Combine iron with vitamin C. Get routine blood work if you’re at risk. And if you don’t feel something, don’t ignore it. Your body is usually trying to tell you something.
