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Iron deficiency and perimenopause: What are the signs?
How hormonal changes during perimenopause can impact iron levels and what symptoms to look out for.
Top things to know about iron deficiency and perimenopause:
Heavy menstrual bleeding is a leading cause of low iron in women and people with cycles worldwide.
Hormonal changes during perimenopause can increase the risk of heavy bleeding.
Untreated iron deficiency can lead to anemia, a condition where the body doesn’t have enough iron to create healthy red blood cells.
Common symptoms of iron deficiency anemia include fatigue, weakness, pale skin, and shortness of breath.
Tracking your bleeding patterns and cycle-related experiences with Clue can help you identify iron deficiency before it becomes anemia.
Perimenopause is the transition phase toward menopause. During perimenopause, reproductive hormones like estrogen and progesterone fluctuate significantly and then decline gradually, causing changes in bleeding patterns (1). Many people experience heavier periods during perimenopause, which can lead to significant iron loss (2). If iron deficiency (low iron) is left untreated, it can impact a person’s work, relationships, physical and mental well-being, and overall quality of life (3). Unfortunately, many healthcare providers seem to be unaware that iron deficiency is also a concern in perimenopause (2). Recognizing iron deficiency in perimenopause can be challenging because symptoms like fatigue, dizziness, and brain fog can easily be mistaken for typical perimenopause experiences (3). Knowing the signs of iron deficiency can help you get a diagnosis and treatment before it becomes anemia (4).
“Low iron puts all organ systems under stress as they work harder to respond and make up for the deficit. The effects of low iron on quality of life during the menopause transition and beyond are increasingly apparent.” - Emma Bardwell, registered nutritionist with Active Iron
Why do we need iron?
Iron is an essential mineral that supports many body functions (5). It helps produce hemoglobin, the protein in red blood cells that carries oxygen throughout the body. Oxygen is crucial for cellular function, energy, and overall health (5). We get most of our iron from food, which is absorbed in the intestines before being stored in the liver as ferritin, a protein. This stored iron is released as needed to create new blood cells (5). If iron stores deplete faster than they can be replenished, it can lead to iron deficiency and iron deficiency anemia (3).
What is the difference between iron deficiency and iron deficiency anemia?
Iron deficiency (ID) means the body has low iron levels (5). It is the most common nutritional deficiency worldwide, largely affecting girls and women of reproductive age (5). If ID is untreated, it can lead to iron deficiency anemia (IDA) (6).
In fact, 30% of non-pregnant women and 37% of pregnant women worldwide are affected by anemia (7). Iron deficiency accounts for about three-quarters of all anemia cases (5).
IDA occurs when the body lacks enough iron to maintain healthy red blood cells to transport oxygen (5). Anemia can significantly affect your health and quality of life, so early detection and treatment are essential (6).
What are the symptoms of ID/IDA?
Recognizing the symptoms of ID/IDA can be challenging because they can easily be attributed to other conditions (2). Symptoms can begin when iron levels are low and gradually increase in severity as ID progresses to IDA.
Common symptoms of ID/IDA include (2,8):
Fatigue and low energy
Shortness of breath
Weakness
Poor concentration and brain fog
Rapid heartbeat
Headache
Pale or yellowish skin
Brittle nails
Hair loss
Low iron levels can also weaken the immune system, making you more prone to illness (2).
6 in 10 members using Clue Perimenopause who track their energy levels have tracked “exhausted.”
What is the link between perimenopause and iron deficiency?
During perimenopause and while your body is going through hormonal changes, you may experience new physical and emotional changes (1). One of the first signs may be a change in your menstrual cycle. You may notice shorter or longer cycles, heavier or lighter flow, and prolonged periods (9,10).
During perimenopause, it is common for cycles to become unpredictable and for periods to become heavier (10). This may be due to anovulatory cycles—where ovulation does not occur—and conditions like fibroids (non-cancerous growths of muscle tissue in or on the uterus), which become more common during this time (3,11). Heavier periods can lead to substantial iron loss over time, and they are a common cause of IDA in perimenopausal women (3).
Heavy menstrual bleeding (HMB) is defined as excessive bleeding that impacts a person’s quality of life (5). Heavy periods can impact work, relationships, and daily life, especially if they result in ID or IDA (5). Research shows that about 1 in 4 women over the age of 41 may experience HMB (2). HMB is a set of symptoms known collectively as abnormal uterine bleeding (AUB), which also includes disruptions in the frequency, duration, and regularity of menstrual bleeding (12).
At some point, the ovaries stop producing estrogen, and menstrual bleeding stops altogether, marking the end of the reproductive years. Menopause is the complete absence of menstruation for one full year (1). While the average age for menopause is 51, perimenopause can last anywhere from a few months to as long as 11 years (9,13).
2 in 3 members using Clue Perimenopause track heavy periods
The link between estrogen and iron deficiency
During perimenopause, changing estrogen levels can also affect how the body manages iron (14). Estrogen helps the body absorb iron by lowering a hormone called hepcidin, which usually slows down iron absorption. When estrogen levels drop, hepcidin levels can rise, making it harder for the body to absorb iron from food (15). This, combined with heavy bleeding—which is common during this time—can lead to iron deficiency, because the body uses up iron stores faster than it can replace them.
After menopause, iron levels in the body often increase (14). The significant drop in estrogen leads to changes in iron regulation. Without regular blood loss from menstruation, iron may accumulate in the body, and higher levels of ferritin are often observed (14). Some people in menopause may even have too much iron, which can be a health concern (14). However, if someone already had low iron before menopause, they might still need to keep an eye out on their iron intake (16).
The link between thyroid hormones and iron deficiency
Iron levels and thyroid function are closely linked. Thyroid hormones help the body to use iron, while good iron levels support thyroid hormone production (17). Research shows that iron deficiency can disrupt thyroid hormones and raise the risk of thyroid issues. When the thyroid doesn’t work well, it can also make it harder for the body to absorb and use iron. This can increase the risk of iron deficiency (18).
Hypothyroidism, which means having low thyroid hormones, can cause symptoms like fatigue, muscle cramps, changes to hair and skin, and heavy or unpredictable menstrual bleeding. These symptoms are also common during perimenopause due to changes in estrogen and progesterone hormone levels (19). This can make it difficult for healthcare providers to notice hypothyroidism in perimenopausal and menopausal individuals based on clinical symptoms alone (19). As we age, our risk of thyroid dysfunction increases, meaning we’re more likely to have issues with our thyroid in perimenopause and beyond (19). It’s recommended that people with thyroid issues have their iron levels regularly checked and low iron levels treated (17).
What other factors can increase the risk of ID/IDA?
While hormonal changes during perimenopause can impact iron levels, several other factors can contribute to iron deficiency, including:
A diet low in iron: Not eating enough iron-rich foods can lead to deficiency. One study found that more than 9 in 10 menstruating women were not getting enough iron from their diet (2). Vegetarian and vegan diets may increase the risk of iron deficiency since heme-iron (found in meat, poultry, and fish) is absorbed more effectively than non-heme iron (found in fruits, vegetables, and cereals) (20). One study found that 4 in 10 vegan women under the age of 50 were iron deficient (2).
Restrictive dieting and fasting: Many perimenopausal women may turn to restrictive diets or fasting to manage weight during this life stage, often without realizing these approaches can reduce essential nutrients like iron (2). Cutting out foods, especially those rich in heme-iron (like meat), or following intense dieting routines can significantly lower iron levels, which may increase the risk of deficiency over time.
Using a copper IUD: Using a copper IUD may lead to heavier periods, with more than 1 in 4 women using this method found to be iron deficient (2).
Gastrointestinal (GI) conditions: Non-menstrual blood loss can also lead to iron deficiency, and may arise from conditions such as gastritis (inflammation of the stomach), esophagitis (inflammation of the esophagus), ulcers, infections, or tumors in the esophagus, stomach, small bowel or colon. Additionally, conditions such as celiac disease, ulcerative colitis, or Crohn’s disease can hinder iron absorption (8).
Pregnancy: During pregnancy, the body’s demand for iron increases significantly (21). Iron deficiency and anemia during this time can lead to complications for both the pregnant person and the developing fetus (21).
How are iron deficiency and iron deficiency anemia diagnosed?
Currently, there are no guidelines in the USA recommending regular screening for ID among adult women, with screening primarily focused on anemia in pregnant women (22). That means that many cases of ID during perimenopause may go undiagnosed until they progress to IDA (2,6). Tracking your bleeding patterns and related experiences can help you advocate for yourself to get a diagnosis of ID before it becomes IDA.
If your healthcare provider suspects you have ID/IDA, they will ask about your diet and medical history (2). They also may perform blood tests, including:
Complete blood count (CBC): This test helps assess your overall health and detect disorders by measuring your red blood cells, hemoglobin, and other blood components (8).
Ferritin levels: This test checks your body’s iron stores and is crucial for identifying iron deficiency before it progresses to anemia (6).
Once a diagnosis of ID or IDA is made, your healthcare provider may investigate potential sources of blood loss (3). If you’re experiencing heavy menstrual bleeding, an ultrasound of the pelvis and a biopsy of the uterine lining may be performed to identify the source (2). Other tests could include a pregnancy test, thyroid hormone test, a fecal occult blood test to check for blood in the GI tract, and a colonoscopy (a procedure that examines the lower GI tract) (2,10).
How do you treat iron deficiency?
Whether you're experiencing mild symptoms or have been diagnosed with IDA, there are effective strategies to help you replenish your iron stores.
Diet: Incorporate iron-rich foods into your diet, like meat, fish, poultry, leafy greens, legumes, and iron-fortified cereals. Pairing these foods with vitamin C-rich foods, like citrus fruits or bell peppers, can enhance iron absorption (8).
Supplementation: While dietary intake is important, iron supplements are often the first-line treatment for both ID and IDA (5). There are various types of supplements with different iron amounts, but higher doses aren’t always better. Taking too much iron can lead to side effects like constipation or nausea, and studies suggest that taking an iron supplement every other day is just as effective as taking one daily, with fewer side effects (23). Your healthcare provider can help to find the right dose for you.
Intravenous iron therapy: When oral therapy isn’t tolerated or doesn’t work quickly enough, intravenous (IV) iron therapy (administered through the veins) can be an option. However, this method is typically more expensive and may have additional side effects (5).
When to see a healthcare provider
If you’re concerned about iron deficiency, especially if you experience heavy bleeding, reach out to your healthcare provider. Soaking through a pad or tampon every two hours or having periods that last longer than eight days can increase your risk for iron deficiency and anemia (24,25). Your healthcare provider can help determine the cause of your symptoms and discuss treatment options if you suspect heavy bleeding and low iron.
Depending on the cause, they may suggest hormonal birth control methods, like combined oral contraceptives or hormonal IUDs, to regulate and reduce bleeding (10). Non-hormonal medications, such as ibuprofen and tranexamic acid can also help manage blood loss (10,26). If needed, surgical options are available, including myomectomy (removing fibroids), uterine artery embolization (blocking blood flow to the uterus to shrink fibroids), endometrial ablation (removing or destroying the uterine lining), and hysterectomy (removing the uterus and sometimes the ovaries and fallopian tubes), which is a permanent solution for severe cases (25).
If you experience any bleeding after reaching menopause, consult a healthcare provider, as it may require further evaluation (27). You can use Clue to track your bleeding patterns, energy levels, and experiences like brain fog or forgetfulness. Tracking your experiences can provide helpful insights for any discussions you have with healthcare providers. Keep in mind that healthcare providers may not routinely screen for low iron or anemia in perimenopausal individuals, so it’s essential to speak up if you feel something isn’t right (28).
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FAQs
Should I get my iron levels checked?
The International Federation of Gynecology and Obstetrics recommends that all women and girls who menstruate should be regularly screened for iron deficiency, and not just anemia (29). Unfortunately, this recommendation hasn’t been widely implemented in primary care in the USA. Current guidelines from the American College of Obstetricians and Gynecologists only recommend screening for iron deficiency anemia during pregnancy (22).
If you think you may have iron deficiency, make sure to speak to your healthcare provider and ask them to check both your hemoglobin and ferritin levels (5). Vegans and vegetarians should get their iron levels checked regularly since they may be at a higher risk for iron deficiency (30).
Should everyone be taking iron supplements?
Not necessarily. Most people should be able to get all the iron they need by eating a varied and balanced diet (20). Before taking any supplement, it’s important to assess your individual needs with a healthcare provider.
How much iron does a woman need during perimenopause?
Daily iron needs can vary, but generally, women in perimenopause may require about 18 mg of iron per day (20). People in the USA are usually able to get the recommended amount of iron from their diet; however, those with heavy menstrual bleeding may require iron supplementation (20). Consulting a healthcare provider can provide personalized recommendations.
Can I have iron deficiency in menopause?
Once you reach menopause, your period stops and you no longer lose iron through menstruation (31). As a result, your daily iron requirements decrease from about 18 mg per day before menopause to about 8 mg per day post-menopause (20). In menopausal women, the most common causes of iron deficiency anemia (IDA) are chronic gastrointestinal bleeding or absorption issues related to gastrointestinal conditions such as celiac disease and inflammatory bowel disease (16).
The information provided is for educational purposes and should not replace professional medical advice. Always consult a healthcare provider for personalized health and wellness guidance.
