The Iron Myth
When we are tired or have low energy, doctors automatically think about testing iron levels. But why exactly do we need iron, why do we become deficient, and how can we make sure our food sources match our lifestyle?
Iron is found in every single cell of our body and in all plant and animal tissues in trace amounts. It is an essential mineral that has a role in our metabolism and bodily functions (mainly transporting oxygen from the lungs to the rest of the body as part of hemoglobin).
As you may have guessed, the role of iron is crucial. All our cells, muscles and organs need oxygen to perform their daily functions. An essential mineral is a substance that has to be obtained from external sources, as our body cannot synthesize it itself. If we lack iron, we will produce less hemoglobin and less oxygen will be delivered to our tissues, leading to fatigue, lack of stamina, anemia, a weakened immune system, and many other symptoms.
“Iron is the most prevalent nutrient deficiency in the world.”
Myth #1 Iron makes you stronger
Yes and no
Iron deficiency will decrease your endurance and athletic performance but supplementing while you are not deficient will not make you stronger.
Iron is involved in red blood cell formation and oxygen transport and utilization, and iron can improve the oxygen-carrying capacity of the cells, therefore improving aerobic performance. However, supplementing will not make you stronger, increase your muscle mass nor help you “lift”. Iron deficiency reduces your VO² max, endurance capacity, and performance. If you feel prematurely fatigued when performing aerobic or endurance training, supplementing in iron may be a good idea, as it will increase the flow of oxygen reaching your muscle tissues when exercising, therefore your heart will not have to pump as hard to get the same amount of oxygen flowing. If you were deficient, you will see a difference after supplementing with iron as it will increase your exercising capacity, oxygen uptake, reduce your heart rate and decrease lactate concentration.
Myth #2 Low iron = anemia
No
You can have iron deficiency without being anemic.
There are 3 main stages of iron deficiency:
Storage iron is depleted: when a blood test reveals serum ferritin below 18 ng/ml
Functional deficiency: red blood cell formation starts to be impaired.
Iron-deficiency anemia: blood tests reveal hemoglobin levels below 12 g/100 ml and ferritin levels below 12 ng/ml.
Anemia is basically a reduction in the number of red blood cells and a reduced capacity of the blood to carry oxygen. The main symptom is extreme fatigue due to a lack of oxygenation and a buildup of carbon dioxide in the body. Anemia being the last stage of iron deficiency, many of the consequences of iron deficiency can be felt before reaching the anemic stage. Over 30% of the world population is anemic.
Myth #3 Women are more prone to iron deficiency than men
Yes
It is estimated that at least 30% of female athletes have iron deficiency.
Women in general are more at risk of being deficient because of menstrual blood loss. About 1 in 30 menstruating women in the US lose more iron than they take in.
Myth #4 There is only one type of iron
No
Two types of iron coexist in nature: heme iron and non-heme iron. All vegetable sources contain the nonheme form, which is poorly absorbed and utilized by our body. Heme iron is bound to hemoglobin and myoglobin (in muscles) and found in animal sources (mainly beef and liver). About 10% to 30% of ingested heme iron is absorbed. There is good evidence that combining heme and nonheme foods improves the absorption of nonheme iron.
Myth #5 Vegans do not need iron supplements
Depends
Plant sources of iron (nonheme) are more difficult to absorb by our organism, with absorption rates below 10%. Therefore, vegans might have trouble obtaining sufficient iron from the diet alone, unless they have a very diverse diet consisting mainly of quality whole foods. Another pain point for plant-based eaters is that phytates and oxalates (antinutrients present in whole grains and vegetables) may bind to some of the iron and make it unabsorbable, “stealing” several minerals from the body.
Vitamin B12 is also needed to transport iron into our red blood cells, and vegans are at a greater risk of B12 deficiency, further increasing the potential risk of iron deficiency. If a consistent plant-based diet is followed, it would be a good idea to consider some form of iron supplementation. As a rule of thumb, vegans should consume around 1.8x the recommended amount of iron-rich foods to those who consume animal products.
Examples of iron-rich food sources
Who is more at risk of iron deficiency?
If you fall within one or more of the following categories, you should be increasing your intake of iron-rich foods:
Children
Teens
Elderly
Women in their reproductive years and pregnant/breastfeeding women
People practicing high-impact sports (running, CrossFit, football, etc.)
People who consume large amounts of coffee/tea/sugar/antacids
How will I know if I am iron-deficient?
According to the WHO, iron deficiency can have negative effects including fatigue, impaired physical performance, and decreased work productivity. Most common symptoms include tiredness, chronic fatigue, pallor, headaches, lightheadedness, abnormal breathlessness during exercise, irritability, constipation, palpitations, loss of endurance and power.
Iron supplements?
The best way to know if you need an iron supplement is through a blood test.
If you do need supplements, choose one in the form of iron bisglycinate or iron picolinate, as these are the easiest to absorb for your body. Stay away from iron sulfate, which is generally cheaper but very harsh on your intestines and less absorbable.
Take your iron away from tea, coffee, and sugary foods, as they can hinder its absorption. Iron is best taken with foods high in vitamin C, as they work synergistically for a better absorption, i.e.: citrus fruit (squeeze a lemon on your greens), kiwis, bell peppers, guavas, etc.
Iron taken along copper, cobalt or manganese has better chances to be well absorbed. Calcium can compete with iron absorption, so calcium supplements and calcium-rich foods should be taken separately from iron supplements.
Tip: cooking with an iron skillet adds iron to your food and makes it more available for absorption.
Recommended doses
If you think you may have iron-deficiency anemia, you should consult with your doctor who will prescribe a blood test (serum iron, ferritin, transferrin or TIBC). You should not supplement in iron as a preventative measure if you do not present iron-deficiency symptoms. In fact, the body has no specific mechanism to rid itself of excess iron and possible dangers of high doses include digestive issues such as pain and constipation. Excess iron may also reduce the absorption of zinc. It is unlikely to overload on iron while following a plant-based diet, however taking iron supplements can lead to excess iron, this is why consistent consumption of iron-rich foods for long-term maintenance of iron levels is the healthiest option.
The Recommended Dietary Allowance (RDA) for iron varies greatly depending on your gender, age, diet, medical conditions, and gut health. I recommend you check the following guidelines for detailed information on your specific needs. For example:
Men 19+ years: 8 mg daily (15 mg for vegetarians/vegans)
Women 19-50 years: 18 mg daily (32 mg for vegetarians/vegans)
Women 51+ years: 8 mg daily (15 mg for vegetarians/vegans)
Pregnant women 19-50 years: 27 mg daily (49 mg for vegetarians/vegans)
Breastfeeding women 19-50 years: 9 mg daily (16 mg for vegetarians/vegans)
Stay below 45mg/day from food + supplements combined.