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Levels of iron, a mineral crucial to oxygen transport in the body, must be carefully monitored. Since iron isn't easily absorbed, ingesting a regular amount is important. Being aware of the benefits of healthy iron levels, knowing how much to ingest based on specific factors, and symptoms of iron deficiencies, is important.


Iron is crucial to healthy red blood cells. Conversely, an iron deficiency can result in anemia. Iron is important because it carries oxygen. Hemoglobin, which is a protein that transfers oxygen from the lungs and transports it to cells,1 relies on a sufficient amount of iron in the body.

Different Forms of Iron

There are two types of iron. Heme iron is responsible for highest iron absorption levels. It comes from meat, and it's present in hemoglobin. It is easier for the body to absorb than other forms of iron, which makes it easy to get necessary iron levels from meat. Non-heme iron is present in a variety of vegetarian sources, such as plants.2 Non-heme iron is also present in foods that have been intentionally fortified with iron, such as certain brands of flour. However, the downside to non-heme iron is that is more difficult for the body to absorb. Thus, it is difficult to get appropriate iron levels from non-heme iron.

Benefits of Iron

Iron is crucial to "a wide variety of metabolic processes, including oxygen transport, DNA synthesis, and electron transport."3 It's difficult for under-oxygenated cells and tissues to perform their functions. Under-oxygenation leads to poor circulation and fatigue. While this can lead to a variety of health issues, it makes it more difficult to keep up an exercise routine that allows your body to reap the benefits of regular physical movement. If muscle tissues doesn't receive enough oxygen, it makes it hard to gain anything from exercise. Additionally, cardio is harder if the amount of oxygen the body already intakes is not being utilized efficiently.2,4 Appropriate levels of iron also helps bolster the immune system. Iron is especially beneficial for pregnant women, since low iron levels can lead to premature births.

However, this is not to say that unusually high levels of iron are the solution, either. According to medical experts who researched biochemical factors associated with iron absorption, they stated the issues associated with too much iron:

Iron overload can be particularly damaging to the heart, liver, and endocrine organs. Excess ferrous iron forms free hydroxyl radicals via the Fenton reaction that cause damage to tissues through oxidative reactions with lipids, proteins, and nucleic acids. Thus, dietary iron absorption and factors affecting bioavailability in the body are tightly regulated where possible.2


How to Use Iron

There are multiple ways to ingest iron. As discussed earlier, heme iron is present in many meats. Non-heme iron is present in plants and iron-fortified foods. However, since iron is not easily absorbed by the body, iron supplements are often recommended. Being aware of what multivitamins you consume is a good start. Comparing them to the recommended dosage for your gender, age, and other health factors will let you know if there's enough iron already present. In the case of a serious medical emergency, physicians may recommend blood transfusions.

Daily Recommended Allowances

Since men naturally have higher iron levels than women, the recommended dosages are different. For male teenagers, the recommended daily allowance is 11 mg. For female teenagers, 15 milligrams is recommended. For men between the ages of nineteen to fifty, eight milligrams is recommended. For women in the same age range, 18 mg is the daily recommended allowance. For both men and women over 51, the recommended dosage is the same: 8 mg.5

Symptoms of an Iron Deficiency

It is sometimes difficult for individuals to recognize iron deficiencies. The symptoms can often be attributed to other issues, such as a lack of sleep. However, when taken together, the following symptoms are a good sign of a need to see a medical professional to test for iron deficiencies. Extreme fatigue, lack of energy, shortness of breath, weight loss, inability to engage in usual physical activities, are typical signs for adults. However, the symptoms can be much worse if the low iron level is severe or chronic. According to health care experts, it may manifest in children by causing "cognitive impairments and developmental delays."4 Tachycardia, or worsening congestive heart failure, are also symptoms of iron deficiency.

Sometimes, if the situation is pronounced enough, simply resolving the situation by increasing iron intake is not enough. Iron deficiencies could, in some cases, be indicative of internal bleeding, or similarly serious issues.

Who May Be at Risk for Deficiencies

Women who menstruate heavily could be at risk for a deficiency. Iron is present in hemoglobin, and blood loss can result in catastrophically low iron levels. Usually, women aged 19-50 are most at risk for iron deficiencies. Additionally, young children between the "ages of 12-36 months are iron-deficient and one-third of these young children develop anemia."4 People who donate blood often could also be at risk for iron deficiencies. Additionally, families below the poverty line sometimes face higher risks of a deficiency. This is because low iron levels are often associated with a poor diet. Women who are pregnant may also be at risk, due to blood loss and iron required by infants for growth. Due to their fast growth and development, infants can also be at risk after they are born. This is especially true if their mothers had iron deficiencies to begin with.

Food That Contain Iron

Luckily, there are many food rich in iron. Red meat and fish are both good sources of iron. Since absorbing iron isn't easy for the body taking optimal amounts of vitamin C can help the body absorb.5 In North America, flour is often fortified with iron as well. Also, taking multivitamins into account is important, since many often include iron anyway.

Sources and Citations

Johnson-Wimbley T, Graham D. Diagnosis and management of iron deficiency anemia in the 21st century. Therap Adv Gastroenterol. 2011;4(3):177-184. [PMC]
Ems T, Huecker M. Biochemistry, Iron Absorption. StatPearls.
Lieu P, Heiskala M, Peterson P, Yang Y. The roles of iron in health and disease. Mol Aspects Med. 2001;22(1-2):1-87. [PubMed]
J. Warner M, T. Kamran M. Anemia, Iron Deficiency. StatPearls. Published November 14, 2018. Accessed January 7, 2019.
Office of Dietary Supplements - Iron. National Institutes of Health. Published January 7, 2019. Accessed January 7, 2019.
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