Let’s talk about iron. Yes, the same strong metal used in the weights you pump at the gym, the power lines that bring electricity to your house, and the frame of that supports the car you drive. In its elemental form, iron is also a metal our bodies simply can’t live without. Iron is essential.
There are a number of life-sustaining functions performed by the iron in our bodies. Humans and most other life forms depend on iron for oxygen transport, chemical reactions, energy production, and DNA synthesis.1,3 Iron is a very reactive element, meaning it is essentially never unbound to other elements or molecules. Its use in the body is related to where it binds. The majority of bodily iron (about 66%) is bound to the hemoglobin molecule in red blood cells– a testament to the important role of hemoglobin in circulating oxygen. This may explain why adequate iron intake is a means of maintaining healthy blood.2 Iron binds to ferritin for storage and to transferrin for distribution.5 Other areas of iron-binding include myoglobin in the muscle, proteins in the liver, and enzymes in the nervous system, just to name a few.
Though all functions involving iron are important, few are more notable than its role in immune function. Compounds vital to immune cell function are synthesized through use of iron-containing enzymes. Such compounds allow the body’s defenses to guard our bodies from invading bacteria. Iron is so universally necessary, there are even mechanisms by which our bodies withhold iron from being used by these invading bacteria using a hormone called hepcidin.3
Low iron is common but can be serious. Certain diseases can cause excessive iron, but a more common problem is low iron. The effects of low iron levels in the body are related to anemia. Anemia is defined as a lower than normal amount of hemoglobin in the blood. Signs and symptoms of anemia include difficulty breathing with exertion, fatigue, dizziness, a pale tongue, spoon-shaped fingernails, rapid heart rate, and heart palpitations.3,4 Iron deficiency is the most common nutritional deficiency worldwide.
If not dangerously low, iron can be supplemented through vitamin tablets and through nutritional choices. Plant-based foods rich in iron include:
- Raisins
- Apricots
- Beans
- Peas
- Almonds
- Broccoli
- Spinach
- Collard greens
- Wheat
- Oats
- Brown rice5
Only about 10 to 30 percent of the iron you consume is absorbed and used by the body.6 Animal sources of iron contain heme and are more easily absorbed. 5 Some examples include:
- Sardines
- Oysters
- Beef
- Chicken
- Tuna
Recommended blood levels of iron and dietary needs differ based on sex, age, and other health conditions, such as pregnancy. Work with your health care provider or registered dietician to learn more and to make a goal for your iron levels.
References
1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3999603/
2. https://www.hsph.harvard.edu/nutritionsource/iron/
3. https://lpi.oregonstate.edu/mic/minerals/iron
4. https://ufhealth.org/iron-diet
5. https://www.hsph.harvard.edu/nutritionsource/iron/
6. https://www.ucsfhealth.org/education/hemoglobin-and-functions-of-iron
