What Does Iron Do For The Body?

Dec 12, 2022 Iron

What Does Iron Do For The Body?

Quick Health Scoop:

  • The amount of Iron you need each day is determined by several factors including your age, gender, and current dietary intake
  • Heme Iron is found in animal sources of foods like meat, poultry, and seafood, while non-heme Iron can be found in a variety of plant foods like breakfast cereals, white beans, and lentils
  • Iron can support a healthy pregnancy and supports healthy energy levels
  • Infants, young children, teenage girls, pregnant women, and premenopausal women are more prone to Iron deficiency

What is Iron?

Iron is an important mineral needed to keep your body healthy. From growth and development to cellular functioning Iron plays a critical role in many processes throughout your body. [1]

Your body needs Iron to make hemoglobin, a protein found in your red blood cells that carries oxygen from your lungs to every part of your body. Iron is also needed to make myoglobin, a protein that delivers oxygen to your muscles. [1]

Iron is a key nutrient for healthy brain development and growth in children. Additionally, adequate amounts are needed for the production of certain hormones in your body.[9]

How Much Iron Do You Need Per Day?

The amount of Iron you need each day is determined by several factors including your age, gender, and current dietary intake. Generally speaking, most men need roughly 8 mg of Iron per day while women should aim for 18 mg, and increase their intake to 27 mg during pregnancy. [2]

The higher amounts needed for women are due to the blood loss that occurs during menstruation. Additionally, the need for Iron increases during pregnancy to help deliver oxygen to blood cells, tissues, and organs while supporting the healthy growth of the developing baby.[2,4]

Teens aged 14-18 years are actively growing and require higher amounts of Iron: 11 mg for boys, and 15 mg for girls. [2]

Women, ages 51 and older need approximately 8 mg of Iron per day. This lower number accounts for the onset of menopause. However, some women experience menopause later, in which case they should follow the RDA for women aged 19-50 until menopause has started. [2]

Sources of Iron

Iron can be found naturally in a variety of foods but can also be found in foods that are fortified with the mineral, like wheat and other flours.

Iron from food comes in two forms: heme and non-heme. Heme Iron is found in animal sources of foods like meat, poultry, and seafood, while non-heme Iron can be found in a variety of plant foods. Plant foods that contain non-heme Iron include whole grains, leafy greens, nuts, seeds, soy, and legumes.

Heme Iron has a higher bioavailability than non-heme Iron meaning it is more easily absorbed by your body. In fact, your body can absorb roughly 40% of the heme Iron you consume. [2] Non-heme Iron, on the other hand, is less bioavailable than heme Iron as your body can only absorb between 2% and 20% after eating it. [2]

However, your body will absorb Non-heme Iron more efficiently when you pair it with foods that contain Vitamin C such as citrus fruits, strawberries, sweet peppers, tomatoes, and broccoli. For example, pairing your iron-fortified cereal with Vitamin C-rich orange juice will help to enhance iron absorption. Additionally, adding vegetables that are high in Vitamin C like sweet peppers to a tofu stir-fry will help increase Iron absorption.

The richest sources of heme Iron include oysters, beef, canned sardines, chicken, tuna, and eggs.[1]

The richest sources of non-heme Iron include breakfast cereals fortified with Iron, white beans, lentils, tofu, kidney beans, chickpeas, tomatoes, potatoes, and green beans. [1]

Iron Benefits

Beyond providing oxygen to the organ systems throughout your body, Iron provides the following health benefits: †

Supports a healthy pregnancy

Iron is especially important during pregnancy to meet the high demands of rapid growth and development. [7]

During pregnancy, your blood volume increases by nearly 50%. This allows your body to produce more red blood cells to help deliver oxygen and nutrients to your growing baby. [3]

Without adequate Iron, your body may not be able to produce enough red blood cells to maintain a healthy blood supply. [4]

Support athletic performance

Iron is required to make myoglobin, the protein that delivers oxygen to your muscles.Therefore, Iron is especially important for athletes, particularly athletes that participate in endurance training like marathon running.

Supports healthy energy levels

Considering how Iron is essential for delivering oxygen to all of your tissues and cells so that they can produce energy, it’s no wonder Iron can help support healthy energy levels.[8]

Women with low ferritin levels (a protein that may be a sign of Iron deficiency) who are experiencing low energy levels may benefit from an increase in Iron. One study found that women with reported fatigue who took 80 mg of an Iron supplement, experienced improved energy levels. [5] Be sure to consult with a healthcare professional to identify what nutrients meet your body’s needs.

Iron Deficiency and Shortfalls

Approximately 10 million people in the United States are iron deficient with approximately 5 million who have Iron deficiency anemia. [8] In fact, 1 in 10 US adult premenopausal women (ages 15-49 years) are deficient in Iron. [6]

Other groups at risk for Iron deficiency include infants, young children, and pregnant women. [1] Infants, particularly those born preterm and those whose mothers have Iron deficiency are at risk for Iron deficiency as they don’t have the iron stores needed for rapid growth. [1]

Young children, especially those that are picky eaters, may not consume adequate amounts of Iron-rich foods, placing them at risk for a deficiency. Furthermore, pregnant women need additional Iron to support the increased blood volume needed to supply oxygen to their baby.

Iron deficiency occurs when your body doesn’t have adequate Iron to make hemoglobin, an important component of your red blood cells that enables them to carry oxygen throughout your body.

Iron supplements

People in the United States generally get adequate amounts of Iron from their diets, but infants, young children, teenage girls, pregnant women, and premenopausal women are prone to Iron deficiency.

Additionally, people who don’t eat a balanced diet rich in foods containing Iron or that take medications that may affect Iron levels in the body, may benefit from Iron supplementation.

Iron pills work to restore low Iron levels when getting Iron from food just isn’t enough.

Multivitamin and multi-mineral supplements with Iron, especially those designed for women, typically provide 18 mg of Iron which is 100% of the DV. However, Iron-only supplements usually provide around 65 mg of Iron which is 360% of the DV. [1]

If you suspect you have an Iron deficiency, you should discuss the correct dosage of Iron supplementation with your healthcare provider to ensure you are getting the right amount to meet your individual needs. The most common type of Iron supplement will be found in pill form, however, you can find Iron gummies as well.

There are certain foods that can interfere with the absorption of Iron which include spinach, dairy, eggs, whole grains, and caffeine. It’s best to avoid having these foods at least one hour before and after you take an Iron supplement.

How do I know my Iron pills are working?

 Although you may not feel any different after taking iron supplements for a few days, your iron levels should increase. However, it can take several months to build up the Iron reserves in your body.

The Bottom Line

The amount of Iron you need each day is affected by several factors including your age, gender, and current dietary restrictions.

Heme Iron derived from animal sources like meat, poultry, and seafood, is more easily absorbed than plant-based non-heme Iron. However, when non-heme Iron sources like whole grains, leafy greens, nuts, and seeds are paired with Vitamin C, absorption is increased.

While many people may be able to meet their Iron needs through diet, others like infants, young children, teenage girls, pregnant women, and premenopausal women prone to Iron deficiency. If you are concerned about Iron deficiency, talk to your healthcare provider to see if you may benefit from Iron supplements.

The benefits of Iron supplements can be far-reaching for people experiencing an Iron deficiency.

Learn More About Iron:

  Approximately 10 million people in the United States are iron deficient with approximately 5 million who have iron deficiency anemia. [7]

† These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.


  1. Office of Dietary Supplements - Iron (2022). Accessed October 7,  2022, from https://ods.od.nih.gov/factsheets/Iron-HealthProfessional/
  2. Institute of Medicine (US) Panel on Micronutrients. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington (DC): National Academies Press (US); 2001. 9, Iron. Available from: https://www.ncbi.nlm.nih.gov/books/NBK222309/
  3. Soma-Pillay P, Nelson-Piercy C, Tolppanen H, Mebazaa A. Physiological changes in pregnancy. Cardiovasc J Afr. 2016 Mar-Apr;27(2):89-94. doi: 10.5830/CVJA-2016-021. PMID: 27213856; PMCID: PMC4928162.
  4. Abbaspour N, Hurrell R, Kelishadi R. Review on iron and its importance for human health. J Res Med Sci. 2014;19(2):164-174. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3999603/
  5. Effect of Iron supplementation on fatigue in nonanemic menstruating women with low ferritin: a randomized controlled trial. Paul Vaucher, Pierre-Louis Druais, Sophie Waldvogel, Bernard Favrat CMAJ Aug 2012, 184 (11) 1247-1254; DOI: 10.1503/cmaj.110950
  6. Devarshi PP, Legette LL, Grant RW, Mitmesser SH. Total estimated usual nutrient intake and nutrient status biomarkers in women of childbearing age and women of menopausal age. Am J Clin Nutr. 2021 Apr 6;113(4):1042-1052. doi: 10.1093/ajcn/nqaa392. PMID: 33567452; PMCID: PMC8023996.
  7. Brannon, P. M., & Taylor, C. L. (2017). Iron Supplementation during Pregnancy and Infancy: Uncertainties and Implications for Research and Policy. Nutrients9(12), 1327. https://doi.org/10.3390/nu9121327
  8. Miller JL. Iron deficiency anemia: a common and curable disease. Cold Spring Harb Perspect Med. 2013;3(7):a011866. Published 2013 Jul 1. doi:10.1101/cshperspect.a011866 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3685880/
  9. Fisher AL, Nemeth E. Iron homeostasis during pregnancy. Am J Clin Nutr. 2017;106(Suppl 6):1567S-1574S. doi:10.3945/ajcn.117.155812 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5701706/
  10. Elizabeth L Prado, Kathryn G Dewey, Nutrition and brain development in early life, Nutrition Reviews, Volume 72, Issue 4, 1 April 2014, Pages 267–284, https://doi.org/10.1111/nure.12102


Emily Hirsch, MS, RD

NatureMade Contributor

Emily has over a decade of experience in the field of nutrition. In her writing, she strives to bring lackluster research on health and nutrition topics to life. She loves writing about GI health and women’s issues. Find her at www.southcharlottenutrition.com

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