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. 

REFERENCES 

  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 

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