Iron Deficiency and Infertility

Iron deficiency and infertility

By: Ana Reisdorf, MS, RD

Iron deficiency is a common condition in which there’s an inadequate supply of iron in your bloodstream. It’s the most prevalent nutritional deficiency, even affecting people in developed countries like the United States and is one of the leading health care burdens around the world.[1]

If you are struggling to conceive, you may want to speak to your doctor about your iron levels as this common deficiency may be a contributor to infertility.

Why Getting Enough Iron Matters

Iron is an essential mineral for growth, development, and everyday metabolic functions, like creating some hormones and neurotransmitters. It’s also responsible for making a protein called hemoglobin a functional oxygen carrier, which is distributed throughout your bloodstream via red blood cells. 

Hemoglobin transports oxygen from your lungs to every other part of your body, and another protein called myoglobin that provides oxygen to muscles. As such, iron plays a direct role in oxygenation.

Iron deficiency can be asymptomatic early on because your body will initially use iron that is stored in various organs, like the spleen, liver, bone marrow, and muscles. 

If these stores are too low, the most common side effect is feeling fatigued due to a lack of oxygen in the body and the shrinking of red blood cells. Once you get to that stage, this is considered iron deficiency anemia. 

You may also experience trouble concentrating, and more severe symptoms like swelling of the tongue, pale skin, brittle hair and nails, and decreased appetite. You may also be more susceptible to becoming sick. 

Adult women ages 19-50 should be getting 18 mg of iron per day (10 mg more than men need). Pregnant women require 27 mg per day to meet the needs of both mom and baby.[2]. 75% of this iron should come from Heme Iron according to the research used to develop the USDA’s RDA’s.

Iron Deficiency and Women

Women experience iron deficiency more frequently than men. In fact, the World Health Organization estimates that approximately one-third of all women of childbearing age, and at least 40% of pregnant women worldwide, are anemic.[3]

There are a number of reasons for this discrepancy, such as:

  • Not consuming enough iron in the diet
  • Not consuming other foods that optimize iron absorption
  • Blood loss through menstruation for premenopausal women, especially those who experience heavier periods
  • Having a gastrointestinal condition that may inhibit iron absorption, like inflammatory bowel diseases[4]

Women who are pregnant are also at a heightened risk for iron deficiency anemia, due to the redirection of nutrients toward the growing fetus. However, for women who cannot become pregnant, iron deficiency anemia may be a significant contributing factor. 

Iron Deficiency and Infertility

Untreated iron deficiency anemia can make it more difficult for a woman to become pregnant and can increase her risk for infertility. While research is ongoing, there’s no question that deficiencies in micronutrients have been associated with fertility obstacles among women. 

This is seen in the case of developing amenorrhea due to iron deficiency anemia, when the body no longer menstruates as it attempts to minimize further iron losses. This is estimated to occur among approximately 50% of women of child-bearing age with iron deficiency anemia.[5] Many women who are deficient in iron also experience anovulation, meaning they do not ovulate, or have poor egg health due to inadequate oxygenation of cells.[6]

Several animal models have shown a significant correlation between severe iron deficiency and fertility. For instance, a 2014 study found that compared to healthy rats in a control group, rats with iron deficiency experienced substantially lower conception rates.[7]

Another study published in 2020 found that iron restriction depressed ovary function in rats and reduced fertility. It also found that this was reversible through the feeding of a normal diet that included adequate iron.[8]

Human research has observed similar outcomes. A 2006 study of 18,555 premenopausal women with no history of infertility were followed for eight years with assessment of dietary intake and changes in fertility. Four hundred thirty-eight women reported infertility due to ovulatory disorder. It was found that women who took iron-containing supplements and consumed iron-rich foods had a significantly lower risk of infertility compared to those who didn’t.[9]

Sources of Iron

There are many sources of iron that can be incorporated into the diet. There are two distinct types of iron ionic irons (salts, chelates, proteinates, etc) and Heme Iron.  Including iron-rich foods regularly can help make sure you’re getting enough. 

Some of the best food sources of iron include: 

  • Red meat, such as beef and lamb (Heme Iron)
  • Liver (Heme Iron)
  • Chicken (Heme Iron)
  • Salmon and tuna (heme Iron)
  • Eggs (Ionic Iron)
  • Legumes, including beans, peas, and lentils (Ionic Iron)
  • Tofu (Ionic Iron)
  • Broccoli (Ionic Iron)
  • Dried fruit like raisins, prunes, figs, and apricots (Ionic Iron)
  • Peanut butter (Ionic Iron)
  • Enriched breads and grains (Ionic Iron)

Additionally, vitamin C helps optimize dietary Ionic iron absorption. Pairing ionic iron-rich and vitamin C-rich foods together can help your body utilize more iron overall. 

This is also why most Ionic iron supplements, another reliable source of this critical mineral for women, also contain vitamin C.  It should be noted that combining Ionic Iron with Vitamin C causes significant oxidative stress in the gastric mucosa.  Heme Iron supplements absorb better than Ionic irons and do so without the addition of Vitamin C.

Why Heme Iron is Best

There are two types of iron: heme and non-heme. 

Heme iron, which is derived from animal sources, is more readily absorbable by the body than nonheme iron, which comes from plants. While nonheme iron tends to be 2-20% bioavailable, heme iron bioavailability sits around 15-35%.[10] The remaining unabsorbed, unused iron from these sources can be released into the body and cause irritation.  When taken with food, as most people do, nonheme iron absorption is very very low as food interferes with its absorption.  Heme Iron absorbs at high levels with or without food, but the presence of heme iron has been shown to increase absorption of dietary non-heme iron as well.

In addition to diet, iron supplements are a reliable source of this essential mineral, especially for women concerned about infertility. While most iron supplements are of nonheme form, ProFerrin uses the heme form of iron. This proprietary blend uses a molecular ring (heme ring) around the iron as it’s directed to the bloodstream. This ring prevents any excess free iron from being released into the intestines and irritating digestive lining. 

On the other hand, non-heme iron supplements can cause upset stomach and changes in bowel regularity, including diarrhea and constipation. Absorption rates can be affected by things like drinking coffee and tea, or eating other nutrients in your diet, whereas heme iron is not.[11,12] Non-heme (Ionic) iron is also shut down by hepcidin, a chemical released in response to inflammation (as in pregnancy or arthritis), whereas Heme Iron absorbs well even when hepcidin is in the blood stream.

If you’re looking to improve fertility and have identified iron deficiency as a problem, heme iron supplements, such as Proferrin, are a great option for a high-quality iron supplementation. 


  1. Pasricha SR, Tye-Din J, Muckenthaler M, Swinkels DW. Iron deficiency. The Lancet, 397 (10270):233-248. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)32594-0/fulltext 
  2. “Iron.” National Institutes of Health, Office of Dietary Supplements. Updated 10 Dec 2019. Access 16 Feb 2021. Available from: https://ods.od.nih.gov/factsheets/Iron-Consumer/ 
  3. “Anaemia.” World Health Organization. Accessed 16 Feb 2021. Available from: https://www.who.int/health-topics/anaemia#tab=tab_1 
  4. Gasche C, Lomer MC, Cavill I, Weiss G. Iron, anaemia, and inflammatory bowel diseases. Gut. 2004;53(8):1190-7. doi: 10.1136/gut.2003.035758
  5. Tonai S, Kawabata A, Nakanishi T, Lee JY, Okamoto A, Shimada M, Yamashita Y. Iron deficiency induces female infertile in order to failure of follicular development in mice. J Reprod Dev. 2020;66(5):475-483. doi: 10.1262/jrd.2020-074.
  6. Sathiyanarayanan S, Sundar JS, Madhankumar EK, Praneetha A, Kalaiselvi S, Gopinath PM, Dakshayani D, et al. A study on significant biochemical changes in the serum of infertile women. Int J Curr Res Aca Rev. 2014;2(2)96-115. http://www.ijcrar.com/vol-2-2/Sasikumar%20Sathiyanarayanan,%20et%20al.pdf 
  7. Li YQ, Cao XX, Bai B, Zhang JN, Wang MQ, Zhang YH. Severe iron deficiency is associated with a reduced conception rate in female rats. Gynecol Obstet Invest. 2014;77(1):19-23. doi: 10.1159/000355112
  8. Tonai S, Kawabata A, Nakanishi T, Lee JY, Okamoto A, Shimada M, Yamashita Y. Iron deficiency induces female infertile in order to failure of follicular development in mice. J Reprod Dev. 2020;66(5):475-483. doi: 10.1262/jrd.2020-074
  9. Chavarro JE, Rich-Edwards JW, Rosner BA, Willett WC. Iron intake and risk of ovulatory infertility. Obstet Gynecol. 2006;108(5):1145-52. doi: 10.1097/01.AOG.0000238333.37423.ab
  10. Monsen ER. Iron nutrition and absorption: dietary factors which impact iron bioavailability. J Am Diet Assoc. 1988;88(7):786-90. https://pubmed.ncbi.nlm.nih.gov/3290310/ 
  11. Seligman PA, Moore GM, Schleicher RB. Clinical studies of hip: An oral heme-iron product. Nut Res. 2000;20(9):1279-1286. doi:10.1016/S0271-5317(00)00215-3 
  12. Lynch SR. Interaction of Iron with Other Nutrients. Nut Rev. 1997;55(4):102-110. doi:10.1111/j.1753-4887.1997.tb06461.x 

RDA of Iron

My Supplement Has 100% of the RDA of Iron but My Iron is Still Low?

If you find yourself wondering why you are taking enough iron but you are still iron deficient, you may be taking the wrong type of iron. There are two types of iron. One is ionic iron which is manufactured in a laboratory from chemicals and the other is Heme Iron which is derived from bovine red blood cells. Heme Iron absorbs far better than does ionic iron. All Proferrin® products are Heme based iron supplements, ensuring that you are taking the only supplement you need to support healthy iron levels.

How does this relate to your iron supplement? The USDA publishes RDA’s based on the amount of a vitamin or mineral that you should ingest daily in order to maintain healthy levels. According to the Institutes of Medicine version the RDA of Iron includes a very important footnote (click on Elements Table .pdf file at bottom of page). That footnote says that the RDA “assumes” that you are getting 75% of that daily Iron intake amount from Heme Iron sources. So, if the iron in your supplement is ionic iron (virtually all of them are) the RDA really doesn’t mean anything relative to the iron supplement you are taking. Thus, it is very easy to be taking an iron supplement that supposedly meets the RDA, but still be low in iron, because not enough of the ionic iron is absorbing into the bloodstream to meet your body’s demand for iron. The only sure way to ingest enough absorbable iron is to take a Heme Iron supplement such as Proferrin®*. Furthermore you need to make sure that in your supplement the total number of milligrams of elemental iron in the form of Heme Iron is high enough to meet at least 75% of the RDA of Iron. There is only one supplement that contains 100% of its iron in the form of Heme Iron. That iron supplement is Proferrin®, and it contains a proprietary Heme Iron called Heme Iron Polypeptide. You will easily obtain the remaining 25% in the form of inorganic iron found in other foods such as enriched flours or grains used to make breads and cereals.[1]

Below is a table, which lists the recommended daily allowance of iron, with an adjoining column that showing the RDA recommendation when 75% of that intake comes from a Heme Iron source. The Institute of Medicine recommends that 75% of your iron intake comes from a Heme Iron source (e.g. lean meat, eggs, and seafood). Most iron supplements do not contain Heme Iron, which means if you are supplementing your iron, but not taking Proferrin®, you may not meet your recommended iron intake*.

GenderUSDA – RDA75% of RDA (Heme Iron)
Males8 – 11 mg. (age dependent)6 – 8.25 mg.
Females8 – 18 mg. (age dependent)6 – 13.5 mg.
Pregnancy27 mg.20.25 mg.

* This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.


  1. Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc : a Report of the Panel on Micronutrients. Washington, DC: National Academy Press; 2001.

PPI’s & Iron Deficiency

“Iron Deficient?

Have GERD or frequent Indigestion?”

Then you’re probably taking a Proton Pump Inhibitor (PPI) like Prilosec, Prevacid, Dexilent, Aciphex, or Protonix.  If so, you should be taking Proferrin® because PPI’s can and do impair absorption of non-heme iron. Your “typical” iron supplement won’t help if you’re taking a PPI,  according to Dr. Sharma (gastroenterologist).1

“These cases presented suggest that omeprazole-induced achlorhydria may impair the response to oral iron therapy”1  

“A hypochlorhydric state, therefore, would impair predominantly, the absorption of non-heme iron.”1   

If you are taking a PPI, Proferrin® heme iron is your best choice by far.

Why you should choose Proferrin® brand Heme Iron Polypeptide (HIP):

  • The ONLY Heme iron sourced from USDA edible red blood cells
  • Lowest cost per mg of Fe (as HIP) in the U.S. market
  • Multiple published “peer reviewed” medical studies using Proferrin® 2,3,4,5
  • Maintains healthy iron levels 3,4,5

Visit Proferrin.com to buy Proferrin® or to learn more about the Proferrin® brand and the science behind our products.


  1. Tempel, Mila et al. “Effects of omeprazole on iron absorption: preliminary study.” Turkish journal of haematology : official journal of Turkish Society of Haematology vol. 30,3 (2013): 307-10. doi:10.4274/tjh.2013.0042
  2. Seligman, PA, Moore, GM, Schleicher, RB. Clinical studies of hip: An oral heme-iron product. Nutrition Research. 2000;20(9):1279-1286. doi:10.1016/S0271-5317(00)00215-3.
  3. Nissenson, AR, Berns, JS, Sakiewicz, P, et al. Clinical evaluation of heme iron polypeptide: sustaining a response to rHuEPO in hemodialysis patients. American Journal of Kidney Diseases. 2003;42(2):325-330. doi:10.1016/S0272-6386(03)00658-9.
  4. Ndegwa, Sarah, and Raymond Banks. “Heme Iron Polypeptide (Proferrin®) versus Oral and Injectable Iron Products for the Treatment of Anemia.” Cadtha.ca, 28 Sept. 2007.
  5. Abdelazim IA, Abu-Faza M, Elbiaa AA, Othman HS, Alsharif DA, Elsawah WF. Heme iron polypeptide (proferrin®-ES) versus iron saccharate complex (ferrosac) for treatment of iron deficiency anemia during pregnancy. Acta Med Int 2017;4:56-61

Vitamin C and Iron Absorption

Do I Need Vitamin C with my Iron Supplement?

The answer is mostly no, and it all depends upon which type of iron supplement you take. When considering Vitamin C and Iron absorption, remember that there are two types of iron supplements. Ionic Iron supplements are inexpensive to manufacture and are found in various forms as salts, chelates, polysaccharides, and proteinates. Heme Iron on the other hand is relatively expensive to manufacture and is available in the form of Heme Iron Polypeptide (HIP) which is refined from Bovine Hemoglobin. Heme Iron Polypeptide does not require vitamin C to perform effectively.

Vitamin C and Iron Absorption – How does it Work?

All Ionic Iron supplements require an acidic GI environment in order to properly dissolve and be available for absorption via the ionic transport pathway. Because of this Vitamin C (ascorbic acid) is added to many ionic iron supplements in an attempt to improve the relatively poor absorption of these products. Since HIP is absorbed by a totally different mechanism [1], HIP is far easier to absorb, absorbs more completely, and does not require an acidic GI tract to absorb well. Vitamin C does not help or hinder the absorption of HIP and thus it is not added to HIP containing iron supplements.[2] A little known fact is that the mere presence of HIP actually enhances the absorption of the dietary ionic (non-heme) iron [2] such as additives that are found in “enriched” products like bread, cereals and snack cakes.

Vitamin C and Iron – The Risks

Is there any downside to taking Vitamin C with your ionic iron supplement? The answer is an emphatic YES! “Co-supplementation of ferrous salts with Vitamin C exacerbates oxidative stress in the gastrointestinal tract, predisposing individuals to ulceration, inflammatory disorders, and exacerbation of existing chronic disorders and may cause cancer”. [3] So, while it is inexpensive to take an Ionic iron supplement, adding Vitamin C to enhance absorption (as most such formulations do) may not be in the best interest of the individual taking the iron supplement. A better approach would seem to be to gain absorption via taking Heme Iron in the form of HIP as a supplement, thereby avoiding the GI oxidative stress associated with taking Ionic irons combined with Vitamin C*.

* This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.


1. Andrews, NEJM 2005; 353:23 pp2508-2509

2. Lynch, et. al., Am. Journal of Clinical Nutrition 1985; 41 pp 13-20

3. Fisher, et. al., Nutrition Journal 2004; 3:2

Women and Iron

Iron Supplements for Women Experiencing Iron Deficiency

Iron deficiency is caused by an insufficient amount of iron in the blood. Inadequate dietary intake of iron can lead to iron deficiency, which can lead to iron deficiency anemia. iron deficiency anemia is a condition in which blood does not have an adequate number of healthy red blood cells, the cells that carry oxygen to the body’s tissues. Without enough iron in your blood, your body just can’t produce enough hemoglobin, the substance in red blood cells that enables them to carry oxygen throughout the body.

Proferrin® ES Heme Iron supplements for women can help maintain iron stores in females with symptoms of iron deficiency. [1] Your doctor can explain how Proferrin® ES works and will be able to determine if you would benefit from this popular Heme Iron supplement. Iron deficiency in women is more prevalent than in men for a variety of reasons including:

  • Blood loss—Women with heavy periods are especially susceptible to iron deficiency anemia because of the amount of blood lost each month. Bleeding from peptic ulcers, colon polyps, or hiatal hernias can also cause iron deficiency anemia. Over-the-counter pain relievers, taken excessively, can lead to gastrointestinal bleeding.
  • Insufficient iron in diet—If you do not consume enough foods rich in iron, you may become iron deficient. Iron-rich foods include meat, eggs and green leafy vegetables.
  • Problems with iron absorption—There are disorders that affect your body’s ability to absorb iron. The small intestine is charged with iron absorption, so if you suffer from an intestinal disorder or if part of your small intestine has been surgically removed, your ability to absorb Iron may be affected.
  • Pregnancy—Many pregnant women are diagnosed with iron deficiency anemia because the iron in their body must nourish the baby, too. [2]

What to do for Iron Deficiency in Women?

Iron supplements are the most commonly used method to maintain healthy iron levels in women. Proferrin® ES and Proferrin® Forte provide nutritional support for those who might be at risk of developing iron deficiency. Proferrin® brand products provide supplementation with lower side effects and are more easily absorbed than iron salts*.[3]

To order Proferrin® ES Oral Heme Iron supplements, visit our Buy Now page.

* This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.


1. K. Suzukawa, et. al., A Study of preventive effects of a high-absorbable iron supplement on an anemia; Prevention of an anemic tendency of Ekiden runner caused by a summer camp. J Physic Fit Nutr Innunol, 1996. 6(1): p. 1-10.

2. Mayo Clinic online. Iron Deficiency Anemia.

3. Seligman, Paul A., et al. “Clinical Studies of Hip: An Oral Heme-Iron Product.” Nutrition Research, vol. 20, no. 9, 2000, pp. 1279–1286., doi:10.1016/s0271-5317(00)00215-3.

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