Iron Deficiency Anaemia in Women: Symptoms, Testing and Treatment
Iron deficiency is the most common nutritional deficiency worldwide and disproportionately affects women of reproductive age. In India, national survey data has repeatedly found anaemia in more than half of women aged 15 to 49. It is also one of the most treatable conditions in medicine, provided the cause is identified rather than only the number corrected.
Deficiency comes before anaemia
Iron stores deplete first, then the supply to red cell production falls, and only then does haemoglobin drop. This means you can have significant iron deficiency with a normal haemoglobin and real symptoms, a state sometimes called non-anaemic iron deficiency. A normal haemoglobin is not a normal iron status.
Symptoms
- Fatigue out of proportion to activity, often the earliest complaint
- Breathlessness on mild exertion
- Dizziness and headaches
- Poor concentration and low mood
- Pale skin, and pallor of the inner eyelid and nail beds
- Cold hands and feet
- Hair thinning
- Brittle, spoon-shaped nails
- Cracks at the corners of the mouth, and a sore or smooth tongue
- Restless legs at night
- Pica, an urge to eat ice, clay or raw rice
- Reduced exercise tolerance and, in athletes, unexplained performance decline
Because these develop slowly, many women adapt and describe themselves as normally tired.
Why women are affected more
Menstrual loss is the leading cause. Heavy menstrual bleeding is common and frequently normalised. Practical markers of heavy loss include soaking through protection in under two hours, passing clots larger than a rupee coin, bleeding for more than seven days, or needing double protection.
Pregnancy increases requirements substantially, with iron transferred to the fetus and blood volume expanding.
Lactation and closely spaced pregnancies deplete stores further.
Diet. Non-haem iron from plant sources is absorbed far less efficiently than haem iron from meat, and vegetarian diets require attention to pairing and inhibitors.
Gastrointestinal causes must not be overlooked: coeliac disease, Helicobacter pylori infection, peptic ulcer, inflammatory bowel disease, hookworm infestation, long-term aspirin or anti-inflammatory use, prior bariatric surgery, and colorectal cancer.
Other causes include chronic kidney disease, long-term acid suppression, which reduces iron absorption, and frequent blood donation.
Testing properly
The essential tests are:
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- Complete blood count, looking at haemoglobin, mean corpuscular volume and red cell distribution width. Iron deficiency typically gives small, pale cells
- Serum ferritin, the main marker of stores. Below 30 ng/mL indicates deficiency, and many specialists treat below 50 if symptoms fit. Ferritin rises with any inflammation, infection or liver disease, so a normal value in the presence of raised CRP does not exclude deficiency
- Transferrin saturation and total iron binding capacity, which help when ferritin is uninterpretable
- CRP, to interpret ferritin
- Peripheral smear
Additional tests depending on context: vitamin B12 and folate, thyroid function, coeliac serology, haemoglobin electrophoresis to look for thalassaemia trait, which is common in parts of India and also produces small red cells, stool testing for occult blood and for parasites, and kidney function.
Serum iron alone is not a useful test. It fluctuates with recent meals and supplements.
Finding the cause
This step is skipped too often. Treating the anaemia without establishing why it developed risks missing a serious source, especially in women over 45, postmenopausal women, and anyone with bowel symptoms, weight loss or a family history of bowel cancer. In those groups, gastrointestinal investigation is appropriate even when heavy periods are also present.
Treatment
Oral iron remains first line. Practical points that markedly improve results:
- Alternate-day dosing is now supported by good evidence. A single daily dose raises hepcidin, which blocks absorption for the next 24 hours, so taking iron every other day can absorb more total iron with fewer side effects
- Take it on an empty stomach, or with a small amount of food if nausea is limiting
- Take it with a source of vitamin C, such as lemon, amla or orange, which improves absorption of non-haem iron
- Separate it by at least two hours from tea, coffee, milk, calcium supplements, antacids, proton pump inhibitors, zinc and high-fibre meals, all of which inhibit absorption
- Expect dark stools, which is harmless. Constipation, nausea and metallic taste are common and often improve with alternate-day dosing or a different salt
- Haemoglobin should begin rising within two to four weeks. Continue for three months after haemoglobin normalises, to refill stores, and recheck ferritin at the end
Intravenous iron is appropriate when oral iron is not tolerated or not absorbed, in inflammatory bowel disease, in chronic kidney disease, in later pregnancy when time is short, before surgery, or when losses exceed what oral replacement can match.
Treat the cause. Options for heavy menstrual bleeding include tranexamic acid, hormonal treatment and a levonorgestrel intrauterine system, which reduces loss substantially. Treating the bleeding is what prevents recurrence.
Dietary iron
Haem sources, which are well absorbed: liver, red meat, poultry, fish.
Non-haem sources: bengal gram, rajma, black chana, lentils, soy, ragi, bajra, amaranth, sesame, jaggery, dates, spinach and other dark leafy greens, and fortified foods.
To improve absorption, pair non-haem iron with vitamin C, use fermentation, soaking and sprouting to reduce phytates, cook in iron vessels, and avoid tea or coffee with meals.
Points of caution
Do not take iron long term without a confirmed deficiency. Iron overload is harmful, and it is a particular danger in undiagnosed haemochromatosis or thalassaemia. Persistent anaemia that does not respond to iron needs reassessment, not a higher dose.
This is general information. Anaemia has many causes, and both the testing and the search for a source should be directed by a doctor.