Why So Many Post Menopausal Women and Older Men Have Low Iron

NOTE: This article was written and posted on August 4, 2019, and was completely updated on July 19, 2026.

Why Is It Hard for Older Adults to Get Iron Tested?

Doctors are often hesitant to order blood tests for post menopausal women who report being more tired or having more hair loss than usual, simply because these women no longer have a period. While menstruation is the most common cause of low iron in younger women, there are multiple reasons why post-menopausal women and men over 50 years of age may be low in iron that warrant investigation.

Practitioner’s Preface

In my almost 18 years of private clinical practice and my licensure in British Columbia, Alberta, and Ontario, I have often found it difficult to have doctors write a Lab Test Request for an iron panel for older men, and especially older women. If they don’t have any obvious signs of blood loss, such as from hemorrhoids, the request to check iron status may be dismissed. This article explains why iron levels are often low in older adults, what routine blood tests can be done, and options should the results come back out of range.

Why Can Low Iron in Older Adults Be Problematic?

Iron is essential for producing red blood cells and for supporting energy and brain function. Low iron status can result in people feeling abnormally tired, weak, having reduced ability to exercise, or even excessive hair loss. These symptoms can occur well before someone develops full-blown iron-deficient anemia.

What is Microcytic Anemia?

Microcytic anemia is when red blood cells are smaller than normal. These smaller cells are less effective at carrying oxygen, which can lead to feelings of fatigue, weakness, and even shortness of breath [3].

How Common Is Low Iron?

Current data indicate that iron deficiency anemia affects approximately 1 in 7 adults over the age of 50 (U.S. data). Fatigue, brain fog, and decreased physical performance are common early signs [2][11].

Why Does Low Iron Happen in Adults Over Age 50?

Chronic Blood Loss

The most common reason older adults develop iron deficiency is slow, chronic blood loss, which can often be from the gastrointestinal (GI) tract. Sources of GI blood loss include ulcers, diverticulosis, colon or rectal polyps, and GI cancer. As outlined in this earlier article about hemorrhoids, when having bowel movements, internal hemorrhoids can bleed microscopically without detection, resulting in low iron status. Blood loss can be subtle and occur over months or years. For this reason, once iron deficiency is detected, older men and postmenopausal women may be referred to a colorectal surgeon for a colonoscopy to rule out polyps or cancer, or for further assessment if internal hemorrhoids are suspected to be the cause [4][5].

Poor Absorption or Dietary Intake

Another reason for low iron status is dietary, which is not exclusive to older adults. Vegans are often low in dietary iron because they avoid consuming all animal products, the main source of heme, the most bioavailable form. Ovo-lacto vegetarians who consume eggs and dairy but avoid eating red meat and seafood such as oysters and clams also tend to have low iron status because these are rich sources of heme.

It is also not uncommon for older people to eat a narrower range of foods as they age, sometimes due to decreased appetite or a deterioration in their ability to chew, resulting from tooth loss.

A common symptom of celiac disease is low iron status, which is why when I have an adult male client of any age with low iron status (without any obvious reasons for it), I request a routine blood test (IgATTG) to rule that out. Since men don’t metastasize/have “periods”, asking for a requisition for this test in men with low iron makes sense. Since people with celiac disease may be asymptomatic, low iron in men of any age is often the only indication to test for it. One might assume that an older man without any symptoms would have already been tested for celiac disease at some point in his life, but sometimes a diagnosis is made only because someone requested the test. While a biopsy is needed to confirm celiac disease, an IgA tTG test to screen for it makes sense in men with low iron lab results.

A Helicobacter pylori (H. pylori) infection can also result in low iron status due to decreased absorption, so requesting a test to rule out H. Pylori is reasonable if no other cause is apparent [5].

Acid-Blocker Medication

Long-term use of Proton Pump Inhibitor (PPI) medications, which are used to treat acid reflux, heartburn, ulcers, and gastroesophageal reflux disease (GERD), reduces stomach acid, resulting in decreased iron absorption [8]. Some common brand names of PPIs include Prilosec (omeprazole), Nexium (esomeprazole), Prevacid (lansoprazole), and Pantoloc (pantoprazole). In adults who have been taking PPIs long-term, a healthcare provider should monitor iron status (and bone status, which is a separate discussion!).

H2 Blockers / Antihistamines

H2 blockers, also called H2 antihistamines, are another class of medications that reduce stomach acid by blocking histamine receptors in the stomach lining. Some common brand names include Zantac (ranitidine), which has been discontinued in Canada for a while, Pepcid and Pepcid AC (famotidine), and Tagamet (cimetidine). Monitoring iron status in older adults who frequently take these over-the-counter medications is important, but if healthcare providers don’t ask if people take them, they won’t know. I ask.

Note: While H2 blockers are most commonly used for heartburn or mild GERD, they are also used in conjunction with “regular antihistamines”, known as an H1 blocker or H1 anti-histamine, for the treatment of Mast Cell Activation Syndrome (MCAS).

MCAS is a condition where mast cells release excessive histamine, causing symptoms including hives, flushing, stomach pain, diarrhea, headaches, and very low blood pressure. The use of both an H2 antihistamine (such as ranitidine (Zantac) along with an H1 antihistamine (such as cetirizine hydrochloride, called Reactine in Canada, and Zyrtec in the US) targets different types of histamine receptors, improving overall symptoms in MCAS. It is important to monitor iron status in those using H2 antihistamines long-term for MCAS.

Whether H2 blockers are used to reduce stomach acid or to manage the symptoms of MCAS, the reduction of stomach acid leads to decreased iron absorption, resulting in low iron status over time [8].

How Iron Is Tested

For adults over the age of 50 with symptoms of fatigue, weakness, shortness of breath, or increased hair loss, I will ask their doctor or clinic for a requisition for blood tests to assess iron status, including a Complete Blood Count (CBC), ferritin, transferrin saturation (TSAT) or serum iron, and Total Iron Binding Capacity (TIBC). If the results come back below lab normal values, then determining the underlying cause, or causes, is next.

Treatment Options for Low Iron

Determine the Cause

When blood tests come back out of range, investigations will include ruling out sources of bleeding, such as internal hemorrhoids that can cause undetectable blood loss while having a bowel movement, ulcers, or whether they may have undiagnosed celiac disease or an H. pylori infection [4][5].

Iron Supplementation

Oral iron supplements are effective for treating low iron in most older adults, and there are many different forms of iron — some with better absorption than others. There are a few newer iron formulations that cause no stomach upset or constipation, and alternate-day dosing can increase absorption [7][10]. Oral treatment will usually continue for several months until ferritin levels (ferritin being the storage form of iron) reach adequate levels, not only hemoglobin levels, which are the iron in red blood cells. In severe cases of iron-deficient anemia, intravenous (IV) iron infusions will often be recommended [9].

Practical Tips for Adults Over 50

Tell your healthcare provider, including your Physician and Dietitian if you feel more tired than usual, easily get out of breath, or have excessive hair loss, as these may indicate that you have low iron status. Routine lab tests can determine if low iron status is underlying the symptoms.

If you have been prescribed PPIs or H2 blockers and have been taking them for several months, someone on your healthcare team should be monitoring your iron status with periodic routine blood tests. If your doctor doesn’t mention it and you think you may have symptoms consistent with low iron, ask to have this tested.

The reason I ask my clients about the medications they take, including over-the-counter medicines, is to better understand their existing lab work and identify areas that may warrant further examination.

I understand that physicians are tasked with limiting any unnecessary tests; however, when clinically justified, not having a lab test in the interest of cost could leave unanswered clinical questions that could be ruled out with a blood test.

When clinically warranted, I will provide my clients’ doctors with my clinical reasons for asking for an iron panel, which is often sufficient to have them issue a requisition.

Should lab results come back out of range, and before a client heads out to buy an “iron supplement,” I will also teach them about the different types of iron formulations that are available, and the advantages and disadvantages of each, and will make recommendations about which type would be the most suitable for them.

Final Thoughts

Doctors are sometimes hesitant to requisition blood tests to screen post menopausal women for low iron status because they no longer have a period; however, blood loss from menstruation is only one cause. Even in men or in post menopausal women who are not prescribed PPIs or H2 blockers, many regularly take over-the-counter antacid tablets that, over time, can affect iron status.

A colonoscopy is recommended for adults over 50 years every ten years to check for colon polyps or cancer, but unless specifically asked, most people won’t volunteer that they have hemorrhoids, which can bleed microscopically, resulting in low iron status. Since slow GI bleeding is often “silent” in older adults [11], having members of your healthcare team ask the right questions and request blood work when necessary is essential. I ask, and if there is an area that warrants further investigation, I will request routine lab tests to be sure.

More Info

If you are an older adult struggling with ongoing low iron status, I can help. Learn about me and the Comprehensive Dietary Package that I offer.

To your good health.

Joy

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Quick Clinical Summary

Q: What are the common causes of low iron in adults over 50?

A: The most common cause in older adults is slow, chronic blood loss from the gastrointestinal tract, often due to ulcers, diverticulosis, polyps, or internal hemorrhoids. Other causes include poor dietary intake (common in vegans/vegetarians), malabsorption from celiac disease or H. pylori, and long-term use of acid-blocking medications.

Q: How do PPIs and H2 blockers affect iron levels?

A: Proton Pump Inhibitors (PPIs) and H2 blockers reduce the production of stomach acid. Since stomach acid is necessary for the proper absorption of dietary iron, long-term use of these medications can lead to a gradual depletion of iron stores and eventually iron-deficiency anemia.

Q: Which blood tests are needed to check iron status in older adults?

A: A comprehensive iron assessment should include a Complete Blood Count (CBC) to check hemoglobin and cell size, along with ferritin (iron storage), transferrin saturation (TSAT) or serum iron, and Total Iron Binding Capacity (TIBC).

References

1. British Columbia Women’s Hospital and Health Centre. Iron deficiency in adults. 2019. [https://www2.gov.bc.ca/gov/content/health/practitioner-professional-resources/bc-guidelines/iron-deficiency]
2. Centers for Disease Control and Prevention. Data brief: Iron deficiency in U.S. adults. 2018. https://www.cdc.gov/nchs/products/databriefs/db519.htm. Accessed November 7, 2025.
3. Merck Manual Professional Edition. (2024). Overview of microcytic anemia. Merck & Co., Inc. https://www.merckmanuals.com/professional/hematology-and-oncology/anemias-caused-by-deficient-erythropoiesis/overview-of-microcytic-anemia
4. American Gastroenterological Association. Gastrointestinal evaluation of iron deficiency anemia guidelines. 2023. https://gastro.org/clinical-guidance/gastrointestinal-evaluation-of-iron-deficiency-anemia/. Accessed November 7, 2025.
5. British Society of Gastroenterology. Iron deficiency in adults: guideline. Gut. 2021;70:203–228. https://pubmed.ncbi.nlm.nih.gov/34497146/. Accessed November 7, 2025.
6. Medscape. Iron deficiency anemia guidelines. 2023. https://emedicine.medscape.com/article/202333-guidelines. Accessed November 7, 2025.
7. Weiss G, Goodnough LT. How I treat anemia in older adults. Blood. 2024;143(3):205–215. https://ashpublications.org/blood/article/143/3/205/494702/. Accessed November 7, 2025.
8. Ganz T, Nemeth E. Inflammation and iron metabolism in older adults. PMC. 2014;5:210–220. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4157323/. Accessed November 7, 2025.
9. Macdougall IC, et al. IV iron therapy in older adults. PMC. 2006;12:115–124. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10808247/. Accessed November 7, 2025.
10. Ashcroft DM, et al. Oral iron in older adults. Blood. 2024;143(3):225–234. https://www.cghjournal.org/article/S1542-3565(24)00410-5/fulltext. Accessed November 7, 2025.
11. Fairweather-Tait SJ, Wawer AA, Gillings R, Jennings A, Myint PK. Iron status in the elderly. Mech Ageing Dev. 2014 Mar-Apr;136-137:22-8. doi: 10.1016/j.mad.2013.11.005. Epub 2013 Nov 22. PMID: 24275120; PMCID: PMC4157323. Accessed November 7, 2025. [https://pmc.ncbi.nlm.nih.gov/articles/PMC4157323/]

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