What Ferritin, B12 and Folate Results Reveal About Anemia and Its Treatment Plan

The results arrive in a patient portal on a Tuesday evening, three rows highlighted in amber: ferritin low, B12 borderline, folate normal. The hemoglobin line, the one that triggered the whole work-up, sits just under the reference range. Nothing dramatic, nothing explained, and a follow-up appointment eight days away.

That gap is where a lot of worry grows. Most people searching for ferritin B12 folate tests anemia want two things: a plain reading of what each number means, and an honest sense of what their care team will do with it. A single low hemoglobin only says that the body is short of healthy red cells. These three tests say why, and the why decides everything that follows.

This explainer walks through how clinicians read the panel together, which patterns matter most, and how the results shape a treatment plan. Every decision stays with the team who ordered the tests; the goal here is simply to make the conversation easier.

How an anemia work-up actually unfolds, step by step

Anemia is a shortage of hemoglobin, the iron-containing protein inside red blood cells that carries oxygen. The World Health Organization sets the usual cut-offs at a hemoglobin below 12 g/dL for non-pregnant women and below 13 g/dL for men, with slightly different thresholds in pregnancy and childhood. A number under that line is a signal, not a diagnosis.

The first clue sits inside the same complete blood count: the mean corpuscular volume, or MCV, which is the average size of a red cell. Iron deficiency tends to produce small, pale cells (microcytic), while B12 or folate deficiency produces large ones (macrocytic). A normal size can mean an early deficiency, two deficiencies pulling in opposite directions, or something unrelated to nutrients at all.

Only after that pattern is noted does the second-line panel make sense. Ferritin estimates iron stores. Serum B12 and folate estimate the two vitamins needed to build DNA inside developing red cells. Many laboratories add transferrin saturation, a measure of how much iron is circulating on its carrier protein, and C-reactive protein, a marker of inflammation that can distort ferritin.

The sequence matters because each result changes how the next one is read. A low ferritin alongside small cells is one of the clearest findings in medicine. A low ferritin alongside large cells makes a clinician look harder at B12. A normal ferritin with a raised inflammation marker proves very little. Reading the numbers in isolation, which is what a portal encourages, is the fastest way to be misled.

Once the deficiency is identified, the work-up turns to cause. Iron does not vanish without a reason, and neither does B12. That search, more than the replacement itself, is what the follow-up appointment is for.

What ferritin, B12 and folate tests each measure

Ferritin is a storage protein. Most of it sits inside liver, spleen and bone marrow cells, holding iron in reserve, and a small amount leaks into the blood in proportion to those reserves. The blood test measures that leak. A low serum ferritin is therefore the most specific single sign that the body’s iron stores are empty, which is why MedlinePlus and the WHO describe it as the preferred first test for iron deficiency.

Vitamin B12 (cobalamin) is absorbed in the final part of the small intestine, but only after it binds to intrinsic factor, a protein made by stomach lining cells. The serum B12 test measures total circulating vitamin, including a large fraction bound to a carrier that cells cannot easily use. That is one reason a borderline result is so common and so hard to interpret on its own; the NIH Office of Dietary Supplements notes that methylmalonic acid and homocysteine, two substances that build up when B12 is functionally short, are often added to settle an ambiguous case.

Folate is the natural form of vitamin B9, found in leafy greens, legumes and fortified grains. Serum folate reflects recent intake and can rise after a single good meal. Red cell folate, measured less often, reflects the average over the lifespan of the red cells, roughly the past few months, and is a steadier guide.

The three tests share one weakness: none of them measures hemoglobin production directly. They measure supply. A person can have low supply with no anemia yet, or anemia with adequate supply because the problem lies elsewhere, such as kidney disease or a bone marrow disorder. The panel narrows the field; the clinician closes it.

What ferritin level is anemic, and what the cut-offs really mean

Strictly speaking, no ferritin level is anemic. Ferritin reports iron stores; the hemoglobin reports anemia. The question people are usually asking is at what ferritin value iron deficiency becomes the likely explanation for their anemia, and here the guidance is specific.

The WHO guideline on ferritin concentrations sets the threshold for depleted iron stores at a serum ferritin below 15 µg/L in otherwise healthy adults and below 12 µg/L in children under five. Where infection or inflammation is present, the same guideline raises the bar to below 70 µg/L in adults, because inflammation pushes ferritin upward regardless of iron status. Many clinical laboratories quote 30 µg/L as a practical working threshold for adults, and a result in the gray zone between the two is commonly treated as probable deficiency when the hemoglobin and cell size agree.

Finding	Typical reading (adults)	What the care team usually considers next
Ferritin below 15 µg/L, no inflammation	Iron stores depleted	Iron replacement and a search for blood loss or malabsorption
Ferritin 15 to about 30 µg/L	Probable deficiency if cells are small	Transferrin saturation; treat if the picture fits
Ferritin normal, CRP raised	Cannot exclude deficiency	Transferrin saturation; repeat after inflammation settles
Ferritin high	Iron overload or inflammation	Assess liver, inflammation, genetic iron disorders
B12 low, folate low	Nutrient or absorption problem	Intrinsic factor antibodies, diet and medication review

Reference ranges printed on a report are population averages, not treatment lines. A ferritin of 20 µg/L may be flagged as normal by one laboratory and as low by another. What changes the plan is the whole pattern, which is why a clinician will rarely act on ferritin alone.

Low iron or low ferritin: which is worse?

The question is a little like asking whether an empty fuel tank or an empty jerrycan is worse. Serum iron is the fuel in the line right now; ferritin is the reserve in the garage. Of the two, the empty reserve is the more reliable warning, and usually the earlier one.

Serum iron fluctuates through the day and with meals, and it falls quickly during any illness. The NIH iron fact sheet describes it as an unreliable stand-alone marker for this reason. A single low serum iron on a morning after a viral infection may mean very little. Ferritin, by contrast, falls only when the body has genuinely run down its stores, so a low value is specific even when the hemoglobin is still normal.

The sequence of iron deficiency makes this clearer. Stores empty first, so ferritin drops. Then the iron circulating on transferrin falls, so transferrin saturation drops. Only after that does hemoglobin production slow, cells shrink, and anemia appear. A person with low ferritin but normal serum iron is at an earlier stage than one with both low. A person with low serum iron but normal ferritin and a raised inflammation marker may not be iron deficient at all.

So the honest answer is that low ferritin is the finding that matters more, because it is harder to produce by accident. The exception is the inflammatory state, where ferritin can read falsely normal while real deficiency hides underneath. In that situation, transferrin saturation, typically read as low when it falls under roughly 20 percent according to NIH guidance, becomes the tie-breaker.

Whichever is low, the practical next step is the same: identify why. Blood loss, poor absorption and increased demand each leave a different trail, and the treatment plan follows the trail rather than the number.

Ferritin low but hemoglobin normal, and when ferritin looks normal but is not

Two patterns cause more confusion than any other on an anemia panel, and they are mirror images of each other.

The first is low ferritin with a normal hemoglobin, often labelled iron deficiency without anemia. The body has spent its reserves but is still managing to build enough red cells. Mayo Clinic notes that this stage can produce fatigue, reduced exercise tolerance and restless legs well before the blood count falls. Guideline bodies increasingly treat it as a condition in its own right, particularly in pregnancy, heart failure and heavy menstrual bleeding, and clinicians will often replace iron at this stage rather than wait for anemia to arrive. Whether to do so in a given case is the treating team’s call.

The second pattern is a normal or high ferritin that conceals real deficiency. Ferritin is an acute-phase reactant, meaning the liver releases more of it during infection, inflammation, cancer, liver disease and obesity. A person with inflammatory bowel disease or rheumatoid arthritis can have empty iron stores and a ferritin comfortably inside the reference range. This is exactly why the WHO guideline lifts its deficiency threshold to 70 µg/L when inflammation is present and recommends measuring C-reactive protein alongside.

Clinicians untangle it with transferrin saturation and, sometimes, a soluble transferrin receptor test, which rises in true deficiency but not in inflammation. In a few cases, the clearest answer comes from a trial of iron replacement under supervision, watching whether the hemoglobin responds.

The practical lesson for a reader staring at a portal: a ferritin inside the range does not close the question if you have a long-term inflammatory condition, and a ferritin below the range matters even when the hemoglobin is holding.

B12 and folate deficiency anemia: what the results show

Red cells need B12 and folate for a single, central job: copying DNA as they divide in the bone marrow. When either is short, the cells keep growing but cannot divide on schedule, so they emerge large, fragile and fewer in number. That is the mechanism behind macrocytic anemia, and it is why the MCV is the first thing a clinician checks when B12 or folate comes back low.

The NHS lists the usual drivers. For B12, the leading cause in many populations is pernicious anemia, an autoimmune condition in which the immune system attacks the stomach cells that make intrinsic factor, so dietary B12 cannot be absorbed no matter how much is eaten. Other causes include a vegan or very low animal-product diet, stomach or bowel surgery, Crohn’s disease, and long-term use of certain acid-suppressing or diabetes medicines that reduce absorption. The NIH fact sheet observes that deficiency becomes more common with age, with survey estimates of roughly 6 percent of adults under 60 and nearly 20 percent of those over 60 in the US and UK.

Folate deficiency more often reflects diet, heavy alcohol use, pregnancy, or conditions that speed up red cell turnover. It develops faster than B12 deficiency because the body stores only a few months of folate but several years of B12.

Interpreting a borderline B12 result deserves patience. Total serum B12 includes vitamin bound to a carrier that tissues cannot use, so a low-normal value can accompany real deficiency, while pregnancy and some medicines can lower the reading without any shortage. Methylmalonic acid and homocysteine help, as do intrinsic factor antibodies when pernicious anemia is suspected. Neurological symptoms such as numbness, tingling and balance problems can appear with B12 deficiency before anemia does, which is why clinicians treat an ambiguous result with respect rather than dismissal.

Can you be anemic and have low B12 at the same time as low iron?

Yes, and the combination is more common than the textbook picture suggests. Mixed deficiency is also the pattern most likely to be missed, because the two shortages push red cell size in opposite directions. Iron deficiency shrinks cells; B12 deficiency enlarges them. Together they can produce a perfectly average MCV sitting beside a clearly low hemoglobin.

The clues to a mixed picture lie in the width of the size distribution, reported as the red cell distribution width or RDW, which rises when a mixture of small and large cells is present, and in a blood film, where a laboratory scientist can see both populations side by side. Any single cause that damages absorption across the stomach and small intestine tends to produce both deficiencies: celiac disease, autoimmune gastritis, weight-loss surgery and long-standing inflammatory bowel disease all appear on the NHS and Mayo Clinic lists for each nutrient separately.

Why does it matter clinically? Because treating only the deficiency that was noticed first can produce a disappointing response and, in the case of folate given while B12 is unrecognized, can allow the neurological effects of B12 deficiency to progress while the blood count improves. Guidelines therefore ask clinicians to check B12 before folate replacement begins and to recheck the full panel when the response to treatment is slower than expected.

For the reader, the useful takeaway is simple. If one nutrient is low, it is reasonable to ask whether the others were measured, and whether the result might have been masked. A normal-sized red cell is not reassurance against deficiency; it is sometimes the signature of two.

Which autoimmune disease causes low iron and B12 together?

Two autoimmune conditions account for most cases in which a single disease empties both stores, and they frequently travel together.

Celiac disease is an immune reaction to gluten that flattens the absorbing surface of the small intestine. Iron is taken up in the first stretch of that intestine, the duodenum, which celiac damages earliest and most severely, so iron deficiency is often the presenting feature, sometimes without any digestive symptoms at all. Folate is absorbed just downstream, and B12 further along, so a longer or more extensive disease can deplete all three. Guideline bodies on both sides of the Atlantic recommend testing for celiac antibodies in any adult with unexplained iron deficiency anemia, which is why that test may appear on a follow-up order without warning.

Autoimmune gastritis is the second. The immune system targets the acid-producing and intrinsic-factor-producing cells of the stomach lining. Loss of intrinsic factor causes pernicious anemia and B12 deficiency. Loss of stomach acid, which is needed to free iron from food and convert it into an absorbable form, causes iron deficiency. The iron shortage often appears years before the B12 shortage, because B12 reserves last so much longer, so a younger person with persistent iron deficiency and no obvious bleeding may be in the early phase of a condition that will later show as pernicious anemia.

Both conditions cluster with autoimmune thyroid disease and type 1 diabetes, and a family history of any of these raises the index of suspicion. The tests used include tissue transglutaminase antibodies for celiac disease, intrinsic factor and parietal cell antibodies for autoimmune gastritis, and, where results are unclear, an endoscopy with biopsies. Which of these a person needs is decided by the gastroenterology or hematology team on the basis of the full picture.

Who usually gets ferritin, B12 and folate tests for anemia, and who is asked to wait

The panel is ordered for almost anyone whose complete blood count shows anemia, and for a good many people who are not yet anemic but belong to a high-demand or high-loss group. The NHS and Mayo Clinic highlight people who menstruate heavily, pregnant and recently pregnant people, frequent blood donors, infants and adolescents in growth spurts, endurance athletes, older adults with limited diets, people who follow vegan or vegetarian patterns, and anyone with a bowel or stomach condition that impairs absorption. Unexplained fatigue in these groups is a common trigger even when the hemoglobin is borderline.

There are also situations in which a clinician will deliberately hold off or repeat before acting. A ferritin drawn during an acute infection or shortly after surgery is likely to read high, so the team may wait for inflammation to settle and recheck, often pairing the repeat with a C-reactive protein. A B12 drawn soon after a person has started a B12-containing supplement, or during pregnancy, may need confirmation with methylmalonic acid before the result is taken at face value. A folate measured the morning after a large salad reflects the salad.

Waiting can also be the right answer when a result is only marginally abnormal and the hemoglobin and cell size are entirely normal. Rather than start replacement on a single borderline value, many clinicians repeat the panel after a defined interval, confirm the trend, and look for a cause in the meantime. This is not neglect; it reflects the fact that supplements can obscure the picture before a diagnosis is secure.

Children, pregnant people and those with kidney disease have their own thresholds and pathways, and the general numbers in this article do not apply to them directly. In every case the decision to test, repeat or treat belongs to the clinician who knows the whole history.

How the results shape the anemia treatment plan

Once the deficiency and its probable cause are identified, treatment has two parallel tracks: replace what is missing, and stop the leak or fix the absorption. The results decide the route, the form and the expected timeline for the first track; the cause decides the second.

For iron deficiency, oral iron is the usual starting point because the gut can absorb it and it is well studied. The mechanism is straightforward: the bone marrow is given the raw material and resumes full-speed hemoglobin production. Response can be tracked early with a reticulocyte count, which measures brand-new red cells and typically rises within days of effective replacement, and later by a hemoglobin recheck. The NHS advises a blood test after the first few weeks to confirm the response, and notes that replacement generally continues for several months after the hemoglobin recovers so that ferritin, the reserve, is rebuilt and not just the circulating count. Intravenous iron is reserved by guidelines for people who cannot absorb oral iron, cannot tolerate it, have ongoing losses that outpace it, or need rapid correction, for example later in pregnancy or before surgery. Which route is appropriate, and for how long, is a prescribing decision.

For B12 deficiency, the cause determines the form. Where the problem is intake, dietary change or oral B12 may be adequate. Where the problem is absorption, as in pernicious anemia, the NHS describes injections that bypass the stomach entirely, with treatment usually continuing lifelong because the underlying autoimmune condition does not resolve. For folate deficiency, the NHS describes a course of folic acid lasting around four months in most cases, always after B12 status has been checked.

Replacement alone is rarely the whole plan. Iron deficiency in a man or postmenopausal woman prompts investigation of the gut for a source of bleeding, often with endoscopy. Heavy menstrual bleeding prompts gynecological review. Suspected celiac disease prompts antibody testing and biopsy before diet change. Treating the number without the cause risks a return to the same amber rows a year later.

What the following weeks usually look like after treatment starts

The first change most people notice is not on a blood test. Mayo Clinic notes that energy often begins to improve within the first week or two of iron replacement, before the hemoglobin has moved much, partly because iron is used by muscle and brain enzymes as well as by red cells. That early lift is real but easy to overinterpret; it is not a signal that the stores are refilled.

Laboratory recovery follows a predictable order. Reticulocytes rise first, usually within the first week, as the marrow responds. Hemoglobin climbs more slowly, typically over several weeks, and the NHS suggests a recheck after about two to four weeks of treatment to confirm that the response is on track. Ferritin recovers last, because the body prioritizes making red cells over refilling storage, and this lag is the reason replacement continues for months after the blood count looks normal. Stopping when the hemoglobin normalizes but ferritin has not is a common route back to deficiency.

B12 replacement produces a similar sequence in the blood count. Neurological symptoms, where present, improve more slowly and more variably; the NHS advises that some nerve-related symptoms can take months to settle and that earlier treatment gives a better chance of full recovery. Folate deficiency responds quickly in the blood, which is one reason it must not be given before B12 is confirmed, since a rising hemoglobin can hide ongoing nerve damage.

During these weeks, oral iron commonly causes constipation, nausea or dark stools. These are expected effects, not signs of harm, but they are worth reporting rather than quietly abandoning treatment, because the care team may adjust the form or route. A slower-than-expected response is a diagnostic clue in its own right and usually prompts a search for ongoing blood loss, poor absorption or a second deficiency rather than simply more of the same.

What people often get wrong about ferritin, B12 and folate results

Myths cluster around this panel because the numbers look simple and the biology is not. A few deserve direct correction.

The first is that a ferritin inside the reference range rules out iron deficiency. It does not, particularly in anyone with inflammation, infection, liver disease or obesity, where ferritin is pushed upward. The WHO guideline’s higher threshold in inflammatory states exists precisely because the ordinary range misleads.

The second is that a normal hemoglobin means iron is fine. Iron deficiency without anemia is an established stage with its own symptoms, and ferritin is the test that detects it. Waiting for the hemoglobin to fall is waiting for the last marker rather than the first.

The third is that eating more iron-rich food fixes a low ferritin. Diet matters for prevention, but once stores are depleted, food alone restores them very slowly, and if the cause is blood loss or malabsorption, diet cannot keep up. The reverse myth, that supplements are harmless to take just in case, is equally wrong: iron accumulates in people with genetic iron overload, and unsupervised B12 or folate can obscure a diagnosis before it is made.

The fourth is that a borderline B12 can be ignored if there is no anemia. Nerve damage from B12 deficiency can precede any change in the blood count, and the NHS specifically warns that delayed treatment can leave lasting neurological effects.

The fifth is that a normal MCV excludes both iron and B12 problems. Mixed deficiency produces average-sized cells from a mixture of small and large ones, and the RDW or a blood film reveals what the average hides.

Finally, many people assume that the replacement is the treatment. For most adults with iron deficiency, the replacement is the easy part; the treatment is finding where the iron went.

Questions to ask your care team about your anemia panel

A follow-up appointment goes better with a short list. These questions are drawn from what patients most often wish they had asked.

• Which of my results actually explains the anemia, and which are incidental or borderline?
• Was an inflammation marker such as C-reactive protein measured alongside my ferritin, and could inflammation be distorting the result?
• If my B12 is borderline, would methylmalonic acid, homocysteine or intrinsic factor antibodies help settle it?
• Were all three nutrients checked, and is a mixed deficiency possible given my red cell size and distribution width?
• What do you think is causing the deficiency, and what tests will look for that cause?
• Should I be tested for celiac disease or autoimmune gastritis, given my results or family history?
• Which form and route of replacement are you recommending for me, and why that one?
• When will my blood be rechecked, which values will you be watching, and what response would you expect by then?
• How long is replacement likely to continue after my hemoglobin returns to normal, and what will tell us the stores are rebuilt?
• Are any of my current medicines affecting absorption or the test results?
• Which side effects should I report, and which are expected?
• Is there anything I should avoid before the next blood test so the results are reliable?

Bringing a written record of symptoms, menstrual history where relevant, diet pattern and all supplements already being taken saves time and improves the interpretation. If a result was taken during an illness, mention it; the timing of a sample can change its meaning entirely.

None of these questions is a challenge to the clinician. They are the same questions a hematologist would ask when reviewing the file, and asking them tends to make the plan clearer for everyone.

When to call your doctor: red-flag signs with anemia or deficiency

Most anemia is managed in primary care over weeks, but some signs need same-day or emergency assessment rather than a routine follow-up. The lists below reflect NHS and Mayo Clinic guidance on when anemia, bleeding or B12 deficiency has become urgent.

Seek emergency care immediately for chest pain, severe shortness of breath at rest, fainting or near-fainting, a racing or irregular heartbeat that does not settle, or confusion. These can indicate that the oxygen-carrying capacity of the blood has fallen far enough to strain the heart and brain.

Seek urgent same-day care for vomiting blood, passing black tarry stools or visible blood in the stool, or heavy bleeding of any kind that does not stop. Black stools after starting oral iron are expected, but black stools before treatment, or alongside dizziness, are not.

Contact your doctor promptly, without waiting for the scheduled review, if you develop new numbness, tingling or burning in the hands or feet, unsteadiness when walking, vision changes, memory or mood changes, or a sore smooth tongue. These can signal B12 deficiency affecting the nervous system, and earlier treatment improves the chance of full recovery.

Also get in touch if iron or vitamin replacement causes severe abdominal pain or vomiting, if a child or someone else in the household may have swallowed iron tablets, which can be dangerous in overdose, if you are pregnant and symptoms worsen, or if you feel no better after several weeks of treatment. A poor response is a clinical clue that deserves a fresh look rather than persistence.

Everything in this article is general information to support a conversation. The decisions about testing, treatment and investigation of cause rest with the clinicians who can examine you and see the whole record.

Frequently asked questions

At what ferritin level is a person considered anemic?

Ferritin does not define anemia; hemoglobin does. Ferritin shows whether iron stores are depleted, and the WHO threshold is below 15 µg/L in healthy adults, or below 70 µg/L where inflammation is present. Many laboratories use 30 µg/L as a working cut-off. Iron deficiency is the likely explanation for anemia when a low ferritin appears alongside a low hemoglobin and small red cells.

What is worse, low iron or low ferritin?

Low ferritin is the more reliable warning. Serum iron swings with meals, time of day and illness, so a single low value may be meaningless. Ferritin falls only when reserves are genuinely spent, so it is specific even before anemia develops. The exception is inflammation, which can hold ferritin falsely normal; transferrin saturation then becomes the deciding test.

What autoimmune disease causes low iron and low B12 together?

Celiac disease and autoimmune gastritis are the usual culprits. Celiac disease damages the small intestine where iron, folate and B12 are absorbed. Autoimmune gastritis destroys the stomach cells that make acid, needed for iron absorption, and intrinsic factor, needed for B12 absorption, leading eventually to pernicious anemia. Both are linked with autoimmune thyroid disease and type 1 diabetes.

Can you be anemic and have low B12 at the same time as low iron?

Yes. Mixed deficiency is common when absorption is impaired by celiac disease, gastric surgery or inflammatory bowel disease. Because iron deficiency shrinks red cells and B12 deficiency enlarges them, the average cell size can look normal. A raised red cell distribution width or a blood film usually exposes the mixed picture, and guidelines ask that all three nutrients be checked.

What does ferritin low but hemoglobin normal mean?

It usually means iron deficiency without anemia: stores are empty but the marrow is still producing enough red cells. Fatigue, reduced stamina and restless legs can occur at this stage. Many clinicians treat it rather than wait for the hemoglobin to fall, especially in pregnancy, heart failure or heavy menstrual bleeding, and the cause still needs investigation.

Why would ferritin be normal if I am still iron deficient?

Ferritin rises during infection, inflammation, liver disease, obesity and cancer regardless of iron status, so it can read normal while stores are empty. That is why the WHO recommends measuring C-reactive protein alongside ferritin and uses a higher cut-off when inflammation is present. Transferrin saturation and soluble transferrin receptor help clarify, and sometimes a supervised trial of iron does.

How is b12 and folate deficiency anemia different from iron deficiency anemia?

B12 and folate are needed to copy DNA in developing red cells, so a shortage produces large, fragile cells and a raised MCV. Iron is needed to build hemoglobin, so a shortage produces small, pale cells and a low MCV. B12 deficiency can also damage nerves before the blood count changes, which iron deficiency does not do.

Is an iron panel the same as a ferritin test, or do I need both?

A ferritin test is a single measure of iron stores. An iron panel adds serum iron, total iron-binding capacity and transferrin saturation, which show how much iron is circulating and available. Ferritin alone is often enough in a healthy person; the fuller panel helps when inflammation is present or the ferritin result is borderline.

How long does it take for ferritin to go up after starting treatment?

Ferritin is the last value to recover. Reticulocytes rise within days, hemoglobin improves over several weeks, and the NHS advises a recheck after about two to four weeks to confirm response. Rebuilding stores takes months, which is why replacement usually continues well after the blood count normalizes. The exact duration is set by the prescribing clinician.

Do I need to stop supplements before ferritin, B12 and folate tests?

Ask the clinician who ordered the test rather than stopping anything on your own. Recent B12 or folate supplements can push results into the normal range and hide a deficiency, and a folate-rich meal can raise serum folate. If you already take supplements, say so, because the team may interpret the result differently or add confirmatory tests.

References

• WHO guideline on use of ferritin concentrations to assess iron status in individuals and populations
• NHS: Iron deficiency anaemia
• NHS: Vitamin B12 or folate deficiency anaemia
• MedlinePlus: Ferritin blood test

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.