Iron & Health
What is Iron & What Does it Do?
Iron is the fourth most abundant element found in the crust of our planet. It is essential for our health in milligram doses and also comes in handy for industrial purposes notably in the production of steel.
In the human body, iron is used in hundreds of different processes daily including:
Transport of oxygen and carbon dioxide in the blood - hemoglobin
Storage and transport of oxygen in the muscles - myoglobin
Energy production in the mitochondria - cytochromes
Oxidative balance - catalase
Defense against pathogens - superoxide dismutase, hydrogen peroxide, etc
DNA repair - Ribonucleotide reductases
And of course, much more
As you can see, iron is an important mineral!
Iron Deficiency:
Iron is a nutrient that our bodies hold onto tightly, and most iron leaves our system through blood loss. Iron deficiency most often occurs during times of increased need, such as rapid growth or illness/injury that results in more iron loss than our reserves can make up for. (1) For this reason, doctors tend to monitor a combination of iron storage levels (ferritin), hemoglobin (iron in the blood cells), and serum iron (free iron in the blood). These tests help us assess our iron status as well as our risk for deficiency or overload.
Iron deficiency builds over time and goes through several stages: (3)
Not enough ferritin. I think of this as having enough money in your checking account but low reserves in your savings account. You are able to support your function for now, but your ability to recover after a loss or period of fewer “deposits” is compromised.
Not enough free iron in your blood. This can start to interfere with blood cell production that may or may not be detectable in blood tests.
Not enough red blood cells are produced and anemia develops.
The smaller number of blood cells that are produced are small and lighter colored due to lack of hemoglobin - now we have a microcytic, hypochromic anemia.
Now symptoms of iron deficiency are easily perceived, and a person will feel more than just a bit worn down.
Signs and Symptoms of Iron Deficiency:
Iron deficiency presents with a constellation of symptoms across many different systems. Iron deficiency is also the most common deficiency world-wide, and similar to iodine deficiency, when iron deficiency presents is also important.
During fetal development, iron deficiency can result in slowed/stunted development. In childhood, iron deficiency is associated with poor learning, delayed cognitive development, and behavioral issues. (1)
At all ages, iron deficiency causes: (1)
Fatigue
Rapid heart rate - tachycardia
Palpitations
Shortness of breath with exertion
Decreased strength and endurance (2)
Intolerance to cold temperatures
Compromised immune function
Pica - craving for non-food items in an unconscious search for iron - crunching ice, eating chalk or dirt, etc
Brittle, deformed nails
Sores at the corners of the mouth
Sore tongue
Difficulty swallowing due to changes in throat muscles and possible development of esophageal webs
Those at increased risk of iron deficiency include: (1)
Fetuses
Infants
Children
Adolescents
Pregnant people
Menstruating people
Vegans/Vegetarians who consume mostly processed foods
People with chronic illness
People with kidney disease
People with atrophic gastritis
People who have received gastric bypass surgery
People taking heartburn/antacid medications
People who donate blood frequently
People with Inflammatory Bowel Disease
People with celiac disease
Where to Find Iron:
Iron is found abundantly in plants and animals. Animal flesh contains iron in the form of hemoglobin and myoglobin which are considered heme-iron. Heme-iron is more easily absorbed in the human digestive system, about 1.8 times better (1). Non-heme-iron is found in plants, especially whole grains and legumes. One surprising source of iron I enjoy in my daily diet is hemp hearts, with one tablespoon containing 0.8 mg of iron. My favorite way to use these protein and omega-3 packed morsels is to sprinkle them on my morning oats, salads, or even treats as they have a light, nutty flavor.
Hemp Milk Recipe:
I also enjoy making hemp milk to use at home:
½ cup hemp hearts + 3 cups water + pinch salt + 1 Tbsp maple syrup + blend until creamy and frothy = 3.5 cups of yummy dairy-free milk! You can hold or adjust the salt and maple syrup for your own preferences.
This milk will separate after sitting for a bit; just be sure to shake it up before use.
While non-heme-iron is less well absorbed than its heme-iron counterpart, there is plenty we can do to improve our absorption. These steps apply to iron supplements too.
Soak and cook your whole grains and legumes to reduce phytic acid content and increase your absorption of the natural iron found in these foods.
Eat good sources of vitamin C along with your non-heme-iron containing foods - broccoli and other brassicas are a surprisingly good source!
Avoid taking/eating high doses of calcium, foods high in soy protein, coffee, or tea at the same meal as high iron foods. They will compete for absorption.
For those of us who choose to abstain from animal products, iron can be a nutrient of concern. “Yet, a vegetarian diet does not appear to be associated with an increased risk of iron deficiency when it includes whole grains, legumes, nuts, seeds, dried fruit, iron-fortified cereal, and green leafy vegetables.” (1) Whole foods and variety for the win yet again!
Daily Intake:
Iron is another of those nutrients that has a sweet spot for intake. We can suffer consequences from too little as well as too much iron.
The recommended daily allowance (RDA) to avoid iron deficiency is 8 mg for non-menstruating adults, 18 mg for menstruating adults, and 27 mg daily during pregnancy.
The upper limit to avoid toxicity is 45 mg daily for adults.
These numbers are elemental iron equivalents - like chewing on iron ore. The iron we consume in our diet only contains a fraction of elemental iron. If you are concerned, be sure to look for conversion tables to determine just how much elemental iron you are consuming.
Toxicity:
Iron toxicity can occur due to poisoning by ingesting toxic levels of iron (above the UL) and progress to death rapidly. The most common cause of this is accidental overdose in children under the age of 6. (1) A rapid response is needed to reduce the amount of iron that is absorbed - calling poison control and following their instructions is vital in these cases.
Accumulated high levels of iron is called iron overload and presents differently. This is most common in people with hereditary iron metabolism disorders such as hemochromatosis which results in over-absorption of iron. Normally a hormone called hepcidin is released when our iron levels are topped off. Hepcidin will decrease the amount of iron absorbed through the digestive tract. For some, hepcidin function is compromised.
For others with chronic illness, iron overload may develop through different mechanisms. In some of these cases, there is a bit of a chicken-and-egg question regarding whether iron overload came first or if the illness created the iron overload. Some illnesses associated with iron overload include: (1)
Cancer - especially liver cancer
Cardiovascular disease
Type 2 diabetes
Neurodegenerative disorders such as Alzheimers and Parkinsons
It should also be noted that not all anemias are caused by iron deficiency. Continuing to treat an anemia with iron can result in iron overload in these cases. If you have chronic anemia that doesn’t respond well to iron supplementation, talk to your doctor about a more thorough investigation into what is causing your anemia. It could be the result of a deficiency of many different nutrients, including vitamin A, B12, folate, or copper.
Prevention of Disease:
From the information we have already covered, you can see how maintaining a healthy iron level can prevent quite a bit of misery. Additionally, good iron balance is also helpful in reducing the risk of complications during pregnancy and birth such as low birth weight, preterm labor, hemorrhage, and maternal or fetal death.
We can also remember that adequate iron levels during pregnancy can help with fetal development as well as physical and neurological development of the infant before solid foods have been introduced. During childhood, adequate iron intake is essential for continued growth and development especially in the areas of learning, behavior, and motor development. Getting good quality nutrition to children is essential for their development in many ways.
Here we see how a deficiency in a single nutrient can have life changing impacts; children who struggle with cognitive and social development grow up and are our community members who must contend with a lifetime of these difficulties and their very real consequences. Adequate nutrition, for us and our neighbors, could go a long way towards strengthening our community. Simply caring for each other through making sure we are all well fed would be a strong commitment to community building and living in a more compassionate world.
Disease Treatment:
When it comes to treatment of disease, we see iron as the best treatment for iron deficiency.
Additionally, we see mixed results with using iron supplementation for the treatment of restless leg syndrome. The mechanism of action for this is not well understood at this point, but iron’s role in neurotransmitter production, especially dopamine, is thought to play a role. (1)
Medication and Nutrient Interactions:
When it comes to medication and nutrient interactions, we are mostly thinking about interactions in the gut that affect absorption. It is recommended to take these substances at least two hours apart from each other.
Substances That Decrease Iron Absorption:
Calcium
Antacids
Cholestyramine (Questran)
Colestipol (Colestid)
Soy protein
Polyphenols
Phytic acid
Substances That Iron Decreases the Absorption of:
Carbidopa
Levodopa
Levothyroxine
Methyldopa
Penicillamine
Quinolones
Tetracyclines
Bisphosphonates
Applications:
Our takeaways this week are:
Iron deficiency is quite common and can have life-altering effects, especially during the prenatal period, early infancy, and early childhood. This is an individual and society level issue of concern.
Iron overload or toxicity is equally problematic and can also lead to long-term illness or death.
Blood loss, poor iron absorption, and low iron consumption are the leading causes of iron deficiency.
Those who are pregnant or who are menstruating have the highest iron requirement.
Iron from animal flesh is the most absorbable, but there are ways to help increase plant iron absorption too.
Next week:
Next week we will investigate magnesium.
To our health!
References:
Higdon, J, “Iron” Linus Pauling Institute, 2001; last update: 2016; accessed January 4, 2022; https://lpi.oregonstate.edu/mic/minerals/iron
Vanek T, Kohli A. Biochemistry, Myoglobin. [Updated 2021 Jul 22]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK544256/
Braunstein, E, “Iron Deficiency Anemia”, Reviewed September 2021, Accessed January 4, 2022, https://www.merckmanuals.com/professional/hematology-and-oncology/anemias-caused-by-deficient-erythropoiesis/iron-deficiency-anemia
Lynch, C, “Esophageal Web” 2020; accessed January 4, 2022, https://www.merckmanuals.com/professional/gastrointestinal-disorders/esophageal-and-swallowing-disorders/esophageal-web
