Intermittent fasting and iron deficiency: why fasting can backfire when your iron stores are low
You fast, you feel drained, and you think your body just can't handle it. Sometimes the reason lies elsewhere: in iron stores that were almost empty before your very first fasting day.
Fasting is a stimulus. A stimulus needs a body that has reserves. If you fast with empty iron stores, you are challenging a system that is already running in power-saving mode.
Does this sound familiar? The first few days of 16:8 feel easy. Then the afternoons start to drag. The stairs feel steeper. Your head turns to cotton wool, and in the evening you lie in bed tired without really being able to switch off.
The obvious explanation is: fasting just isn't for me. Maybe that's true. But maybe it is worth taking a second look before you reach that verdict.
Because there is a deficiency that can cause exactly these symptoms and often goes unnoticed in everyday life. It's called iron deficiency. And it often doesn't get along very well with a short eating window.
"I think my body just can't do fasting."
A woman in her mid-thirties with a demanding job had started intermittent fasting to have more energy. After a few weeks, the opposite had happened.
Her blood count was unremarkable, and her hemoglobin was within the reference range. Her ferritin, on the other hand, was well below the range I aim for clinically. On top of that, she had heavy periods and a mostly vegetarian diet.
We paused the fasting, clarified the causes and replenished her iron stores in a targeted way. A few months later she described having noticeably more energy, and a moderate eating window felt doable for her again. I can't claim causality, but I am documenting the timing.
The lesson: sometimes the problem isn't the fasting, but the starting point you go into it with.
What to expect in this article
- Why a short eating window can mean less iron
- Hepcidin: the doorman at the gut wall
- What studies on fasting and iron status show
- Fasting fatigue or iron fatigue?
- Periods and vegetarian diets as amplifiers
- Why I aim for a ferritin above 100
- Functional deficiency despite a normal blood count
- Three levers before you fast
How I label the evidence
Clinical trial Randomized trials or meta-analyses in humans. The strongest evidence.
Human observation Cohorts, cross-sectional studies, reviews. They show associations, not necessarily causes.
Animal model Data from animal studies. Biologically plausible, but not automatically transferable to humans.
Cell level Data from cell cultures. They explain mechanisms but do not prove a clinical effect.
Fewer meals, fewer opportunities
Imagine your gut as a small harbor. Iron doesn't arrive on big cargo ships, but in lots of small boats. Each meal is a boat. And only a small part of the cargo is actually brought ashore.
Your body has no active way to excrete iron. It regulates its iron balance almost exclusively through absorption. That makes every single meal important, especially when your stores are low.
When you shorten your eating window from twelve to eight or six hours, you often eat not only later but also less often. Three meals and a snack become two meals. That reduces the number of boats that can dock at all.
There is also a practical detail. Many people drink coffee or tea during the fasting period and carry this habit over into their eating window. Polyphenols from coffee and tea can slow the absorption of plant iron when they are drunk with a meal.
With intermittent fasting, the question is usually only when you eat. For your iron, at least as important is what ends up on your plate in that short window. A small window is less forgiving.
And now you know why a fasting plan that is easy for one person can slowly drain the stores of another.
Hepcidin: the doorman at the gut wall
Maybe you've taken iron tablets before and noticed that your levels barely moved. That's frustrating. And it often has to do with a hormone that hardly anyone knows about.
Hepcidin is made in the liver. It works like a doorman. When hepcidin is high, it closes the door at the gut wall through which iron enters the blood. When it is low, the door stays wider open.
Morning: door tends to be open
Hepcidin is comparatively low in the morning. The starting level depends strongly on how full your stores are.
Over the day: hepcidin rises
The rise apparently follows an internal rhythm, not primarily the iron from your food.
After iron intake: door closes
A larger amount of iron can raise hepcidin for about a day. The next portion is then absorbed less well.
Inflammation: door stays closed
Hepcidin also rises with inflammation. Iron is then held back, even when the body needs it.
Hunger: a possible factor
In an animal model, hepcidin rose during a period of starvation. Whether something similar happens in humans during intermittent fasting is an open question.
Human observation In 2013, a team led by Charlotte Schaap at Radboud University in Nijmegen examined how hepcidin changes over the day in 32 volunteers. On one day they ate a low-iron diet, on another the same diet with added iron.
Hepcidin rose over the course of the day on both days. Dietary iron changed this pattern only slightly. The morning baseline was closely linked to ferritin.
What this means for you: your body appears to have its own hepcidin rhythm. Whether your eating window falls earlier or later in the day might therefore play a role in iron absorption. However, this has not yet been tested directly for intermittent fasting.
Schaap CC et al. Clin Chem. 2013. DOI: 10.1373/clinchem.2012.194977Clinical trial At ETH Zurich, a team led by Diego Moretti studied in 2015 how iron doses affect hepcidin in 54 young women with low ferritin. Two years later, the group led by Nicole Stoffel compared daily doses with doses every other day in randomized trials.
After larger amounts of iron, hepcidin was raised 24 hours later, and absorption of the next portion fell by 35 to 45 percent. In the 2017 study, more iron was absorbed overall when it was given every other day.
What this means for you: with iron absorption, more is not simply better. The body actively readjusts. This is literature on physiology and explicitly not a dosing recommendation for you.
Moretti D et al. Blood. 2015. DOI: 10.1182/blood-2015-05-642223 · Stoffel NU et al. Lancet Haematol. 2017. DOI: 10.1016/S2352-3026(17)30182-5Animal model Cell level In 2014, a research group led by Chiara Vecchi in Modena had mice go without food for 24 to 48 hours and additionally studied human liver cells in culture.
During the starvation phase, hepcidin rose, the iron exporter ferroportin was broken down, and iron in the blood fell. This was triggered via signals from glucose production in the liver, for example through the hormone glucagon.
What this means for you: it is biologically plausible that longer periods without food might make the doorman stricter. In humans, this has not yet been conclusively shown for intermittent fasting.
Vecchi C et al. Gastroenterology. 2014. DOI: 10.1053/j.gastro.2013.12.016Metabolism
Iron sits in the enzymes of the respiratory chain in your mitochondria. If it is lacking, energy production in the cell can stall, especially in phases when you are already living off your reserves.
Nervous system
Iron is needed to make dopamine and serotonin. A deficiency can therefore show up as low drive, irritability or poor concentration.
Hormonal system
Glucagon and other fasting signals act on the liver, where hepcidin is made. The thyroid also needs iron to produce its hormones.
Immune system
Inflammatory messengers such as interleukin 6 push hepcidin up. This can hold iron in storage even though the cells urgently need it.
And now you know why it's not only about how much iron you eat, but also about when the door is open.
What studies on fasting and iron status show
You may now be wondering: are there studies that have measured exactly this? The honest answer is: few, and almost never in the people this article is about.
Most fasting studies were done in people with excess weight. In them, ferritin is often raised by silent inflammation in fat tissue. If ferritin falls there, that can even be a favorable sign. In a lean woman with low stores, the same movement means something completely different.
Clinical trial In 2024, a research group led by Jakub Kortas in Gdańsk followed twenty-four older adults for twelve weeks with Nordic walking and a ten-hour eating window.
Ferritin fell in all participants. In those with higher starting values, the drop was larger, and the improvement in long-term blood sugar was linked to the decline in iron stores.
What this means for you: even a moderate eating window combined with exercise can measurably shift your iron stores. If you start high, this may have advantages. If you start low, you have less buffer.
Kortas JA et al. BMC Geriatr. 2024. DOI: 10.1186/s12877-024-04876-8Human observation In 2026, Sandro La Vignera and Rosita Condorelli from Catania analyzed 38 studies on dietary patterns and iron metabolism in obesity in a systematic review. With intermittent fasting, they described a rise in transferrin and a fall in ferritin within physiological limits.
A cohort from Kuwait with 1,087 pregnant women, also published in 2026, found lower ferritin levels in women who fasted during pregnancy than in those who did not. This is an observation and not proof of cause and effect.
What this means for you: the direction of the data points down rather than up. With well-filled stores, this is usually not a problem. With low stores, it might tip the balance.
La Vignera S, Condorelli R. Nutrients. 2026. DOI: 10.3390/nu18162681 · Al-Taiar A et al. Br J Nutr. 2026. DOI: 10.1017/S0007114526107028What is established: forms of fasting can change iron metabolism, and ferritin tends to fall in several studies. What is not established: how strong this effect is in lean, menstruating women with a low starting ferritin. A targeted study on this is missing.
What I describe here is therefore a combination of physiology, indirect data and clinical observation. I consider it plausible. It has not been proven.
And now you know why the question is not whether fasting is good or bad for iron, but which stores you start with.
Fasting fatigue or iron fatigue?
Fatigue has many fathers. When fasting, it is almost reflexively blamed on the fasting itself. That's understandable. It just isn't always the whole story.
More likely adjustment to fasting
- Appears in the first few days and then gets easier
- Hunger and irritability shortly before the eating window
- Improves noticeably after the first meal
- Headache that eases with fluids and salt
Think about iron
- Exhaustion that tends to increase over weeks
- Shortness of breath on stairs, palpitations on exertion
- Hair loss, brittle nails, restless legs in the evening
- Fatigue even on days when you eat normally
Clinical trial In 2003, a team led by François Verdon in Lausanne treated 144 women with unexplained fatigue but no anemia in a double-blind trial. Nine years later, a group led by Paul Vaucher in France repeated the principle with 198 women whose ferritin was below 50 µg/l.
In the first study, fatigue fell by 29 percent with iron and by 13 percent with placebo, and the effect appeared only at a ferritin of 50 µg/l or lower. In the second study, the fatigue score fell by 47.7 percent with iron and by 28.8 percent with placebo.
What this means for you: a ferritin that the lab still considers unremarkable can nevertheless go hand in hand with noticeable exhaustion. Without anemia, this is easily overlooked.
Verdon F et al. BMJ. 2003. DOI: 10.1136/bmj.326.7399.1124 · Vaucher P et al. CMAJ. 2012. DOI: 10.1503/cmaj.110950You are not too weak for fasting. Maybe your body simply lacks the material to process the stimulus well. Exhaustion is information, not a judgment of character.
And now you know why, with fasting fatigue, I measure first before I talk about willpower.
Periods and vegetarian diets: two silent amplifiers
If you menstruate, you lose iron every month. If you eat a vegetarian or vegan diet, you take in iron in a form your body uses less well. Neither is a problem in itself. Both together with a short eating window can become one.
Human observation In 2016, a team led by Stephen Johnson in Columbus, Ohio, analyzed the data of 114 young women with heavy menstrual bleeding. In 2025, a research group led by Lucia Rugeri in Lyon studied a total of 454 women with heavy bleeding.
In Ohio, half had a clearly low ferritin, but fewer than half of them had anemia. In Lyon, ferritin was below 15 µg/l in 42.8 percent and below 30 µg/l in 72.5 percent.
What this means for you: an unremarkable blood count does not rule out iron deficiency. If you have heavy periods, ferritin belongs before any fasting experiment.
Johnson S et al. J Pediatr Adolesc Gynecol. 2016. DOI: 10.1016/j.jpag.2016.05.009 · Rugeri L et al. Int J Gynaecol Obstet. 2025. DOI: 10.1002/ijgo.70352Meta-analysis In 2018, Lisa Haider and colleagues in Vienna pooled the data from 24 cross-sectional studies comparing vegetarian adults with comparison groups.
On average, ferritin was about 30 µg/l lower in vegetarians. In premenopausal women, the difference was around 18 µg/l.
What this means for you: a vegetarian diet can be very healthy. But it needs attention when it comes to iron, and a short eating window leaves less room to compensate.
Haider LM et al. Crit Rev Food Sci Nutr. 2018. DOI: 10.1080/10408398.2016.1259210And now you know why the same form of fasting can lead to completely different results in a man on a mixed diet and in a menstruating vegetarian woman.
Why I aim for a ferritin above 100
Maybe you've been told: your ferritin is within the normal range. And yet you don't feel that way. I encounter this gap between lab result and experience very often in my practice.
I want to be transparent here. A ferritin target above 100 µg/l is my clinical position. It is not a general guideline recommendation for everyone. But I don't base it on gut feeling.
Guideline review In 2015, Laurent Peyrin-Biroulet and colleagues from France compared 29 guidelines on iron deficiency from around the world in the American Journal of Clinical Nutrition.
Their conclusion: for diagnosing iron deficiency, a ferritin cut-off of 100 µg/l should be considered in most situations. Seven guidelines named a ferritin above 100 µg/l as a treatment target. Among the exceptions, the authors named young healthy women with heavy menstrual bleeding, for whom other cut-offs are discussed.
What this means for you: the question of the right ferritin level is scientifically open. A value of 20 or 30 µg/l is not automatically a sign of well-filled stores.
Peyrin-Biroulet L et al. Am J Clin Nutr. 2015. DOI: 10.3945/ajcn.114.103366Functional deficiency: when there is enough and it is still missing
There is a second level. Sometimes iron is present in storage but doesn't arrive where it is needed. Hepcidin keeps the storage door closed, for example with silent inflammation. Ferritin can then look unremarkable while transferrin saturation is low.
A 2021 review in the Lancet emphasizes that clinical and functional limitations can occur without anemia. It also describes how hepcidin holds iron back from the blood during inflammation. That is why I never look at ferritin alone, but always at transferrin saturation and inflammation markers as well.
Review In 2021, Sant-Rayn Pasricha and colleagues from Melbourne, Heidelberg and Nijmegen summarized the state of knowledge on iron deficiency in the Lancet.
They describe hepcidin as the central regulator that limits the absorption of high oral iron doses and absorption during inflammation. In their view, modern parenteral iron preparations have fundamentally changed treatment and allow rapid and safe administration of the total dose.
What this means for you: if tablets are not enough or are not tolerated, there are options today that had a different reputation a few decades ago.
Pasricha SR et al. Lancet. 2021. DOI: 10.1016/S0140-6736(20)32594-0Many people think badly of iron infusions. That reputation largely dates back to the era of older high-molecular-weight preparations. An infusion can be a good option if it is done correctly: with a clear indication, after ruling out iron overload such as hemochromatosis, with a modern preparation and good monitoring. Whether it suits you is always an individual decision.
And now you know why, with exhaustion, I don't just ask whether your ferritin is within the reference range, but whether it is enough for you.
Energy is not a luxury. Energy is the freedom to shape your day yourself. Fasting can be a tool for that. But only if the foundation holds.
Three levers before you fast
You don't have to give up fasting. You can start it more wisely. These three steps are not a therapy, but a sequence I consider sensible.
Measure first, then fast
Before you start, have your ferritin, transferrin saturation, hemoglobin and CRP checked. If you are already fasting and feel exhausted, this applies all the more. If your stores are low, it makes sense to clarify the cause and replenish your stores first, before you shrink your window.
Fill the window with nutrient-dense food
Plan an iron source into every meal, for example legumes, pumpkin seeds, millet, oats or, if you eat a mixed diet, meat as well. Combine plant iron with vitamin C from bell peppers, citrus fruits or berries. Drink coffee and black tea with some distance from your meal.
Choose a window that is earlier and more moderate
If your stores are low, a moderate window with three real meals is often more sensible than a very short one. Whether an earlier window has advantages because of the hepcidin rhythm has not yet been shown, but it is physiologically plausible.
Self-check: is an iron check worthwhile before fasting?
- Your period is heavy or lasts longer than a week.
- You eat a mostly vegetarian or vegan diet.
- You do a lot of endurance sport.
- You have been pregnant or breastfeeding in recent years.
- You take acid blockers or have digestive problems.
- Even before fasting, you are often tired, short of breath or easily cold.
- You are losing more hair than usual, or your legs are restless in the evening.
If you nod at two or more points, that is no reason to worry, but it is a good reason to have blood drawn before your next fasting experiment. And now you know why the smartest first step in fasting is sometimes a lab slip.
Frequently asked questions about intermittent fasting and iron deficiency
Can intermittent fasting cause iron deficiency?
Fasting on its own does not cause blood loss and does not use up iron. It can, however, reduce your intake, because fewer meals also mean fewer opportunities to absorb iron. If your stores are already low, for example because of your period or a vegetarian diet, a short eating window may tip the balance further toward deficiency. There are hardly any studies that look at exactly this question. A 2026 review describes ferritin levels that tend to fall within the reference range during intermittent fasting in people with obesity. For people with depleted stores, that is a reason to measure beforehand.
Why do I feel so exhausted when I fast?
There are several possible reasons: too little energy, too little protein, too little sleep, stress or an adjustment phase. One reason that is often overlooked is iron deficiency that already existed before you started fasting. Iron is needed for oxygen transport, for energy production in the mitochondria and for messenger substances in the brain. In a 2003 randomized trial in the BMJ, the women who benefited most from iron for unexplained fatigue were those with a ferritin of 50 µg/l or lower, even though they had no anemia. So if you feel unusually exhausted while fasting, it may be worth looking at your iron status before you write off fasting, or yourself, as the cause.
What is hepcidin and why does it matter when fasting?
Hepcidin is a hormone made in the liver that works like a doorman at the gut wall. When it is high, less iron from food is let into the blood. A 2013 study in Clinical Chemistry in 32 volunteers showed that hepcidin rises over the course of the day, largely independent of dietary iron. In an animal model in mice, hepcidin rose during a period of starvation via signals from glucose production in the liver. Whether something similar happens in humans during intermittent fasting has not yet been shown. It is biologically plausible, though, that the timing and length of your eating window might help shape how much iron you absorb.
What ferritin level makes sense before fasting?
This is my clinical position and not a general guideline recommendation: I consider a ferritin level above 100 µg/l a sensible target, especially when someone has symptoms and wants to fast. Many labs classify much lower values as unremarkable. A systematic review of 29 guidelines in the American Journal of Clinical Nutrition in 2015 concluded that a cut-off of 100 µg/l should be considered for diagnosing iron deficiency in most situations, with exceptions such as young healthy women with heavy menstrual bleeding. Ferritin is, however, also an inflammation marker. That is why CRP and transferrin saturation belong in the assessment.
Can I have iron deficiency even though my hemoglobin is normal?
Yes, and it is more common than many people think. Iron stores empty long before hemoglobin falls. In an analysis of 114 young women with heavy menstrual bleeding, 50.9 percent had a ferritin below 20 µg/l. Of these women, only 41.4 percent had anemia. In other words, more than half of the cases of iron deficiency would have been missed with a blood count alone. A 2021 review in the Lancet also emphasizes that clinical and functional limitations can occur without anemia.
Is fasting more of a problem on a vegetarian or vegan diet?
It can be an additional burden if your stores are already low. A 2018 meta-analysis pooled 24 cross-sectional studies and found that vegetarian adults had, on average, a ferritin about 30 µg/l lower than comparison groups. In premenopausal women, the difference was around 18 µg/l. Plant iron is absorbed less well and is further slowed by substances such as phytates or polyphenols. If your eating window then shrinks as well, there is less room to compensate. This is not an argument against a vegetarian diet, but for deliberate planning and regular checks.
Does my period matter for iron when I fast?
Yes, a lot. Monthly bleeding is one of the most important reasons for depleted iron stores in premenopausal women. In a French study of 454 women with heavy menstrual bleeding, ferritin was below 15 µg/l in 42.8 percent and below 30 µg/l in 72.5 percent. If you lose iron every month and eat fewer meals at the same time, you are working on both ends of the same equation. Especially with heavy or prolonged bleeding, I think an iron check before starting a fasting program makes sense.
Should I avoid intermittent fasting altogether if I have iron deficiency?
Not necessarily forever, but often for now. My view: first clarify and replenish your stores, then think about fasting. A body with empty iron stores has less buffer for additional stressors. Once your stores are well filled again, a moderate eating window with nutrient-dense meals may be quite compatible for many people. What that looks like in an individual case depends on the cause, blood values and life situation, and belongs in medical supervision.
Which blood values should I have checked before fasting?
For iron status, the basics are ferritin, transferrin saturation, hemoglobin and an inflammation marker such as CRP. Ferritin shows your stores, transferrin saturation shows the iron currently available in the blood, and CRP helps put a ferritin raised by inflammation into context. Depending on the situation, further values such as the soluble transferrin receptor, vitamin B12, folate, thyroid values or celiac antibodies may be useful. Which values are right for you should be decided by a physician.
Is an iron infusion an option if tablets are not enough?
In certain situations it can be a good option if it is done correctly. That includes a clear indication, ruling out iron overload such as hemochromatosis, a modern preparation and good monitoring. The 2021 review in the Lancet describes that modern parenteral iron preparations allow rapid and safe total-dose administration. The bad reputation of infusions largely dates back to the era of older high-molecular-weight preparations. Whether an infusion is an option for you is an individual medical decision.
More from the Fasting Guide
- Fasting for beginners: how to get started
- Intermittent fasting 16:8: what happens in the body
- Fasting for women and the menstrual cycle
- Intermittent fasting for women over 40
- Fasting with Hashimoto's and thyroid conditions
- Fasting, blood sugar and insulin resistance
- Autophagy: when does it begin?
- What breaks a fast?
- Breaking your fast the right way: the first meal
- Fasting-mimicking diet (FMD) explained
Where this topic touches other areas
Iron is a cross-cutting topic. If you recognized yourself in this article, it may be worth looking into these related topics.
Iron deficiency, tiredness and exhaustion
Why empty stores often show up first as a loss of energy.
FerritinFerritin above 100: a sensible target?
The detailed reasoning behind my clinical position.
FunctionalFunctional iron deficiency despite unremarkable ferritin
When iron is there but doesn't arrive where it is needed.
HepcidinIron, inflammation and the hepcidin block
The doorman in detail, and why inflammation can make him stricter.
CycleIron deficiency in women and menstruation
Monthly loss as the most common reason for empty stores.
NutritionIron deficiency on a vegan and vegetarian diet
How plant-based eating and good iron stores can go together.
AbsorptionImproving iron absorption through diet
Combinations that support absorption, and those that slow it.
LabIron deficiency: which blood values count
Ferritin, transferrin saturation and more, explained clearly.
InfusionChecklist for a well-done iron infusion
How you can recognize a correctly performed infusion.
FastingFasting for women and the menstrual cycle
Why the female body reads energy gaps particularly closely.
Sources
All information was checked via PubMed and linked with a DOI. The study type is given in square brackets so you can judge the strength of the evidence yourself.
- Schaap CC, Hendriks JC, Kortman GA, Klaver SM, Kroot JJ, Laarakkers CM, Wiegerinck ET, Tjalsma H, Janssen MC, Swinkels DW. Diurnal rhythm rather than dietary iron mediates daily hepcidin variations. Clin Chem. 2013;59(3):527-35. DOI: 10.1373/clinchem.2012.194977 [Real-world intervention study, crossover, n=32]
- Moretti D, Goede JS, Zeder C, Jiskra M, Chatzinakou V, Tjalsma H, Melse-Boonstra A, Brittenham G, Swinkels DW, Zimmermann MB. Oral iron supplements increase hepcidin and decrease iron absorption from daily or twice-daily doses in iron-depleted young women. Blood. 2015;126(17):1981-9. DOI: 10.1182/blood-2015-05-642223 [RCT, isotope studies, n=54]
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- Kortas JA, Reczkowicz J, Juhas U, Ziemann E, Świątczak A, Prusik K, Olszewski S, Soltani N, Rodziewicz-Flis E, Flis D, Żychowska M, Gałęzowska G, Antosiewicz J. Iron status determined changes in health measures induced by nordic walking with time-restricted eating in older adults: a randomised trial. BMC Geriatr. 2024;24(1):300. DOI: 10.1186/s12877-024-04876-8 [RCT, n=24, older adults]
- La Vignera S, Condorelli R. Effects of the Mediterranean diet, ketogenic diet, and intermittent fasting on iron metabolism and iron deficiency risk in adults with obesity: a systematic literature review. Nutrients. 2026;18(16):2681. DOI: 10.3390/nu18162681 [Systematic review, 38 studies, obesity]
- Al-Taiar A, Ziyab AH, Al-Sabah R, Albatineh AN, Blando J, Hammoud MS. Characteristics of women who fast during pregnancy: findings from the Kuwait Birth Cohort study. Br J Nutr. 2026:1-6. DOI: 10.1017/S0007114526107028 [Real-world cohort, n=1,087 pregnant women]
- Verdon F, Burnand B, Stubi CL, Bonard C, Graff M, Michaud A, Bischoff T, de Vevey M, Studer JP, Herzig L, Chapuis C, Tissot J, Pécoud A, Favrat B. Iron supplementation for unexplained fatigue in non-anaemic women: double blind randomised placebo controlled trial. BMJ. 2003;326(7399):1124. DOI: 10.1136/bmj.326.7399.1124 [RCT, double-blind, n=144]
- Vaucher P, Druais PL, Waldvogel S, Favrat B. Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin: a randomized controlled trial. CMAJ. 2012;184(11):1247-54. DOI: 10.1503/cmaj.110950 [RCT, n=198]
- Johnson S, Lang A, Sturm M, O'Brien SH. Iron deficiency without anemia: a common yet under-recognized diagnosis in young women with heavy menstrual bleeding. J Pediatr Adolesc Gynecol. 2016;29(6):628-631. DOI: 10.1016/j.jpag.2016.05.009 [Real-world observational study, retrospective, n=114]
- Rugeri L, Fruchou Y, Brodbeck C, Bastien M, Lioux A, Gouy G, Cortet M, Dubernard G, Dargaud Y. Evaluation of coagulation disorders and iron deficiency in women with heavy menstrual bleeding. Int J Gynaecol Obstet. 2025;172(1):250-254. DOI: 10.1002/ijgo.70352 [Real-world observational study, n=454]
- Haider LM, Schwingshackl L, Hoffmann G, Ekmekcioglu C. The effect of vegetarian diets on iron status in adults: a systematic review and meta-analysis. Crit Rev Food Sci Nutr. 2018;58(8):1359-1374. DOI: 10.1080/10408398.2016.1259210 [Meta-analysis, 24 cross-sectional studies]
- Peyrin-Biroulet L, Williet N, Cacoub P. Guidelines on the diagnosis and treatment of iron deficiency across indications: a systematic review. Am J Clin Nutr. 2015;102(6):1585-94. DOI: 10.3945/ajcn.114.103366 [Systematic review, 29 guidelines]
- Pasricha SR, Tye-Din J, Muckenthaler MU, Swinkels DW. Iron deficiency. Lancet. 2021;397(10270):233-248. DOI: 10.1016/S0140-6736(20)32594-0 [Review]