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• #1 Vitamin B12 & folate anaemia | NHS inform

  https://www.nhsinform.scot/illnesses-and-conditions/nutritional/vitamin-b12-or-folate-deficiency-anaemia/

  Vitamin B12 or folate deficiency anaemia occurs when a lack of vitamin B12 or folate causes the body to produce abnormally large red blood cells that cant function properly. […] See your GP if you think you may have a vitamin B12 or folate deficiency. These conditions can often be diagnosed based on your symptoms and the results of a blood test. […] A diagnosis of vitamin B12 or folate deficiency anaemia can often be made by your GP based on your symptoms and the results of blood tests. […] Different types of blood tests can be carried out to help identify people with a possible vitamin B12 or folate deficiency. These tests check: whether you have a lower level of haemoglobin (a substance that transports oxygen) than normal, whether your red blood cells are larger than normal, the level of vitamin B12 in your blood, the level of folate in your blood. […] If your symptoms and blood test results suggest a vitamin B12 or folate deficiency, your GP may arrange further tests. If the cause can be identified, it will help to determine the most appropriate treatment.

• #2 Vitamin B12 or folate deficiency anaemia | NICS Well

  https://www.nicswell.co.uk/conditions-and-treatments/vitamin-b12-or-folate-deficiency-anaemia

  Vitamin B12 or B9 (commonly called folate) deficiency anaemia occurs when a lack of vitamin B12 or folate causes the body to produce abnormally large red blood cells that cannot function properly. […] These conditions can often be diagnosed based on your symptoms and the results of a blood test. […] It’s important for vitamin B12 or folate deficiency anaemia to be diagnosed and treated as soon as possible.

• #3 Vitamin B12 or folate deficiency anaemia

  https://www2.hse.ie/conditions/vitamin-b12-or-folate-deficiency-anaemia/

  Vitamin B12 or B9 (folate) deficiency anaemia happens when you have a shortage of either of these vitamins. The body responds by producing abnormally large red blood cells that do not function properly. […] You can usually be diagnosed by a blood test. […] It’s important to start treatment as soon as possible. This is because some problems caused by the condition cannot be reversed. […] Most cases can be treated with injections or tablets to replace the missing vitamins.

• #4

  https://www.nhs.uk/conditions/vitamin-b12-or-folate-deficiency-anaemia/diagnosis/

  A diagnosis of vitamin B12 or folate deficiency anaemia can often be made by a GP based on your symptoms and the results of blood tests. […] Different types of blood tests can be carried out to help identify people with a possible vitamin B12 or folate deficiency. […] It’s also important for your symptoms to be taken into account when a diagnosis is made. […] If your symptoms and blood test results suggest a vitamin B12 or folate deficiency, your GP may arrange further tests. […] Tests for pernicious anaemia are not always conclusive, but can often give your GP a good idea of whether you have the condition.

• #5

  https://111.wales.nhs.uk/encyclopaedia/a/article/anaemia,vitaminb12andfolatedeficiency

  Vitamin B12 or B9 (commonly called folate) deficiency anaemia occurs when a lack of vitamin B12 or folate causes the body to produce abnormally large red blood cells that cannot function properly. […] These conditions can often be diagnosed based on your symptoms and the results of a blood test. […] It’s important for vitamin B12 or folate deficiency anaemia to be diagnosed and treated as soon as possible. […] A diagnosis of vitamin B12 or folate deficiency anaemia can often be made by a GP based on your symptoms and the results of blood tests. […] Different types of blood tests can be carried out to help identify people with a possible vitamin B12 or folate deficiency. […] If your symptoms and blood test results suggest a vitamin B12 or folate deficiency, your GP may arrange further tests. […] You may be referred to a specialist for further tests or treatment.

• #6 Vitamin B12 Deficiency – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK441923/

  Vitamin B12 deficiency can lead to hematologic and neurological symptoms. […] A thorough evaluation of vitamin B12 deficiency should include a complete history and physical with an increased emphasis on gastrointestinal (GI) and neurologic findings. […] In patients with suspected B12 deficiency, initial lab tests should include a complete blood count (CBC) with a peripheral smear and serum B12 and folate levels. […] Serum B12 and folate levels also should be obtained. Folic acid deficiency also presents as macrocytic anemia and is often confused with B12 deficiency. […] After a B12 deficiency confirmation, the etiology must be addressed. […] Blood tests for serum levels of anti-intrinsic factor antibodies may lead to the diagnosis of pernicious anemia. […] Treatment of vitamin B12 deficiency involves repletion with B12.

• #7 Vitamin B12 Deficiency

  https://labtestsonline.org.uk/conditions/vitamin-b12-and-folate-deficiency

  B12 and folate are B complex vitamins that are necessary for normal red blood cell formation, tissue and cellular repair, and DNA synthesis. A B12 and/or folate deficiency reflects a chronic shortage of one or both of these vitamins. […] Over time, a deficiency in either B12 or folate can lead to macrocytic (’large cell’) anaemia, a condition characterised by the production of fewer, but larger red blood cells resulting in a decreased ability to carry oxygen. […] The anaemia and large red blood cells of a vitamin B12 or folate deficiency are frequently detected during a routine FBC (Full Blood Count) test. Laboratory testing is used to detect a deficiency, determine its severity, establish the underlying cause of the deficiency, and to monitor the effectiveness of treatment. […] Frequently requested to diagnose and monitor B12 and folate deficiency: FBC (Full Blood Count). A group of tests requested routinely to screen for blood cell abnormalities. It measures cell types, quantities, and characteristics. With both B12 and folate deficiency anaemia, the amount of haemoglobin may be low and the red blood cells (RBCs) are abnormally large (macrocytic or megaloblastic).

• #8 Megaloblastic Macrocytic Anemias – Hematology and Oncology – MSD Manual Professional Edition

  https://www.msdmanuals.com/professional/hematology-and-oncology/anemias-caused-by-deficient-erythropoiesis/megaloblastic-macrocytic-anemias

  Megaloblastic anemias result most often from deficiencies of vitamin B12 and folate. Diagnosis is usually based on a complete blood count and peripheral smear, which usually shows a macrocytic anemia with anisocytosis and poikilocytosis, large oval red blood cells (macro-ovalocytes), Howell-Jolly bodies (residual fragments of the nucleus), hypersegmented neutrophils, and reticulocytopenia. […] Megaloblastic anemia is suspected in anemic patients with macrocytic indices. It should also be considered in patients with risk factors who have unexplained paresthesias and/or a high RBC distribution width (RDW). Diagnosis is usually based on the peripheral smear. When fully developed, the anemia is macrocytic, with mean corpuscular volume 100 fL in the absence of iron deficiency, thalassemia trait, or renal disease. The smear shows macro-ovalocytosis, anisocytosis (variation in RBC size), and poikilocytosis (variation in RBC shape). […] Serum B12 and folate levels should be measured. […] If vitamin B12 deficiency is confirmed, testing for the presence of autoantibodies to intrinsic factor should be done. […] Treat the cause of B12 or folate deficiency.

• #9 Vitamin B12 Deficiency Anaemia – Armando Hasudungandownloadbookprintpencilchevron-leftchevron-righttwitterfacebookhand-o-rightfilterchainlist-ulenvelopelinkedinangle-rightangle-upyoutubexinginstagramlong-arrow-uppaper-planepinterest-pwhatsappcommentingadd

  https://armandoh.org/disease/pernicious-anaemia/?srsltid=AfmBOorZ36jvYQ0j3Yfu6amaR5BvWen6TsIVxulL2o2AuB7jgye6EJuH

  Vitamin B12 deficiency is a common cause of megaloblastic anemia, a variety of neuropsychiatric symptoms, and elevated serum homocysteine levels, especially in older persons. The recognition and treatment of vitamin B12 deficiency is critical since it is a reversible cause of bone marrow failure and demyelinating nervous system disease […] Clinical manifestations of megaloblastic anemia include pallor, tachycardia, weakness, fatigue, and palpitations. The specific mechanism by which vitamin B12 deficiency affects the neurologic system is unknown […] Classic hematologic expression of vitamin B12 deficiency is a megaloblastic macrocytic anemia characterized by an elevated mean corpuscular volume and mean corpuscular hemoglobin, and a peripheral smear containing macroovalocytes and hypersegmented neutrophils

• #10 Vitamin Deficiency Anemia – Blood Disorders – Merck Manual Consumer Version

  https://www.merckmanuals.com/home/blood-disorders/anemia/vitamin-deficiency-anemia

  Vitamin deficiency anemia results from low or depleted levels of vitamin B12 or folate (folic acid). […] Blood tests can detect abnormal cells that indicate vitamin deficiency anemia. […] Once blood tests show a person has anemia, tests are done to determine if a deficiency of vitamin B12 or folate is the cause. Anemia due to vitamin B12 or folate deficiency is suspected when large (macrocytic) red blood cells and multilobed (hypersegmented) neutrophils (a type of white blood cell) are seen in a blood sample that is examined under a microscope. The blood levels of vitamin B12 and folate are measured, and other tests may be done to determine the cause of the vitamin B12 deficiency.

• #11 Vitamin B12 deficiency – Wikipedia

  https://en.wikipedia.org/wiki/Vitamin_B12_deficiency

  Vitamin B12 deficiency is one of the main causes of anemia. […] Diagnosis is typically based on blood levels of vitamin B12 below 148185 pmol/L (200 to 250 pg/mL) in adults. […] Diagnosis is not always straightforward as serum levels can be falsely high or normal. […] Elevated methylmalonic acid levels may also indicate a deficiency. […] A diagnosis of vitamin B12 deficiency is determined by blood levels lower than 200 or 250 picograms per ml (148 or 185 picomoles per liter). […] Measurement of blood methylmalonic acid (MMA), a vitamin B12-associated metabolite, is a commonly used biomarker. […] Blood tests may show low levels of vitamin B12, elevated levels of methylmalonic acid or homocysteine, and a routine complete blood counts may shows anemia with an elevated mean cell volume.

• #12 Appropriate use of tests for folate and vitamin B12 deficiency – Australian Prescriber

  https://australianprescriber.tg.org.au/articles/appropriate-use-of-tests-for-folate-and-vitamin-b12-deficiency.html

  A full blood count which shows anaemia and macrocytosis should prompt the practitioner to look for a deficiency of vitamin B12 or folate. Tests commonly used for the detection of these vitamin deficiencies are serum folate, red cell folate and serum B12 concentrations. […] Laboratory tests for folate and vitamin B12 are essential for the diagnosis of a deficiency of these vitamins, and for the investigation of some forms of anaemia. […] The usual first test for folate deficiency is assay of serum folate (reference range 7-40 nmol/L*). […] Serum vitamin B12 is the most widely used test for B12 deficiency (reference range 150-600 pmol/L). […] In the investigation of patients with macrocytic anaemia, it is essential to assay both serum B12 and serum and red cell folate in view of the reciprocal changes which may take place in the tests. […] After folate or B12 deficiency has been identified by suitable tests, a cause for the deficiency must be sought.

• #13 Pernicious Anaemia and B12 Deficiency | Doctor

  https://patient.info/doctor/pernicious-anaemia-and-b12-deficiency

  Identification of hypersegmented neutrophils may suggest either vitamin B12 or folate deficiency; however, they are not sensitive in early vitamin B12 deficiency and are not specific. […] Oval macrocytes, hypersegmented neutrophils and circulating megaloblasts in the blood film and megaloblastic change in the bone marrow are the typical features of clinical vitamin B12 deficiency. […] Offer an initial diagnostic test for vitamin B12 deficiency to people who have: At least 1 common symptom or sign, and at least 1 common risk factor for the condition. […] Use either total B12 (serum cobalamin) or active B12 (serum holotranscobalamin) as the initial test for unless: Use active B12 as the initial test for suspected vitamin B12 deficiency during pregnancy. […] Confirmed vitamin B12 deficiency: total B12 less than 180 nanograms (133 pmol) per litre; active B12 less than 25 pmol per litre.

• #14 Megaloblastic anaemia: Folic acid and vitamin B12 metabolism | Revista Médica del Hospital General de México

  https://www.elsevier.es/en-revista-revista-medica-del-hospital-general-325-articulo-megaloblastic-anaemia-folic-acid-vitamin-S0185106315000426

  Megaloblastic anaemia is a general term used to describe a group of anaemias caused by impaired DNA synthesis. It is characterized by abnormal findings in peripheral blood smear (macroovalocytes) and bone marrow samples (megaloblastic hyperplasia). Megaloblasts, the hallmark of these anaemias, are caused by asynchronous maturation between the nucleus and the cytoplasm due to DNA synthesis impairment. […] Clinical presentation supported by common laboratory test findings usually strongly suggest megaloblastic anaemia. For specific diagnosis, however, folic acid and cobalamin levels must be quantified. Sometimes, quantification of intermediary metabolites such as methylmalonic acid and homocysteine may also be required. […] Specific diagnostic tests for folate and cobalamin deficiency. Laboratory studies and diagnostic ranges Situations affecting results Serum folate ng/mL is diagnostic4ng/mL rules out deficiency24ng/mL=quantify methylmalonic acid and homocysteine Falsely low: Pregnancy, alcohol consumption, anti-seizure drugs, temporarily (a few days) deficient diet (with normal intra-enterocyte folate). Falsely elevated: Single intake of folate-rich food. […] Elevated MMA and homocysteine: cobalamin deficiency (sensitivity: 94%, specificity: 99%). Normal MMA and homocysteine: rules out deficiency of both vitamins. Normal MMA and elevated homocysteine: folate deficiency (sensitivity: 86%, specificity: 99%).

• #15 Folate Deficiency Workup: Laboratory Studies, Procedures

  https://emedicine.medscape.com/article/200184-workup

  As the initial test, ruling out cobalamin deficiency is very important because deficiency of folic acid and vitamin B12 produce overlapping neurologic manifestations, and both cause megaloblastic anemia, but folate treatment will not improve neurologic abnormalities due to cobalamin deficiency. The reference range for serum cobalamin is 200-900 pg/mL. […] The usual reference range of serum folate is 2.5-20 ng/mL. By statistical definition, 2-5% of healthy individuals will have a serum folate level of less than 2.5 ng/mL; hence, the serum folate level cannot be used alone to establish the diagnosis of folate deficiency. Therefore, the serum folate test is definitive only when the level is greater than 5.0 ng/mL, which rules out folate deficiency. Otherwise, additional follow-up tests include serum homocysteine (reference range 5-16 mmol/L), which is elevated in vitamin B12 and folate deficiency, and serum methylmalonic acid (reference range 70-270 mmol/L), which is elevated in vitamin B12 deficiency only.

• #16 Testing for Pernicious Anaemia | Pernicious Anaemia Society

  https://pernicious-anaemia-society.org/articles/testing-for-pernicious-anaemia/

  As soon as the Pernicious Anaemia Society was formed it became obvious that some, though not all patients faced a long journey in being diagnosed quickly and accurately. […] And it is only recently that research papers have been published that show that one of the reasons is because the current tests used to diagnose vitamin B12 deficiency in general and whether that deficiency is caused by Pernicious Anaemia are seriously flawed. […] Despite studies consistently demonstrating that no single biomarker of B12 status exhibits the performance characteristics necessary to definitively define status in all patients, the majority of diagnostic laboratories rely solely on serum B12. […] Firstly the current threshold used to diagnose a deficiency may be far too low. […] They classify patients who have a range of B12 between 148 pmol/L and 300 pmol/L as being Subclinical Cobalamin Deficient.

• #17 Diagnosis of Pernicious Anaemia | Pernicious Anaemia Society

  https://pernicious-anaemia-society.org/diagnosis/

  From the very beginning this charity has been made aware that there are serious problems with patients receiving an early diagnosis that will explain their symptoms. […] The problems with diagnosing Pernicious Anaemia begin with the issues surrounding diagnosing B12 Deficiency; these are outlined below: […] Doctors are not looking for B12 deficiency. Thats why its important that you ask your doctor to check your B12 levels. […] There are serious shortcomings with the current test used to determine B12 status in patients. The current test, the Combined Binding Luminescence Test is giving false high results in between 22 and 35% of patients (depending on the manufacturer of the test machine). […] B12 status is not part of the Full Blood Count that is routinely investigated by doctors. Instead most doctors will rely on enlarged red blood cells (megaloblasts) as being an indicator of low B12. However, only around 60% of patients with a B12 deficiency will have enlarged red blood cells (macrocytosis)

• #18 Anaemia, vitamin B12 or folate deficiency – Diagnosing vitamin B12 or folat

  https://www.ibdrelief.com/learn/complications-of-ibd/vitamin-and-mineral-deficiencies-in-ibd/vitamin-b12-and-ibd/anaemia-vitamin-b12-or-folate-deficiency-diagnosing-vitamin-b12-or-folate-deficiency-anaemia

  A diagnosis of vitamin B12 or folate deficiency anaemia can often be made by your GP based on your symptoms and the results of blood tests. […] Different types of blood tests can be carried out to check: whether you have a lower level of haemoglobin (a substance that transports oxygen) than normal, whether your red blood cells are larger than normal, the level of vitamin B12 in your blood, the level of folate in your blood. […] These tests can often help identify people with a possible vitamin B12 or folate deficiency, but they are not necessarily conclusive, because some people can have problems with normal levels of these vitamins, and others can have low levels despite having no symptoms. […] This means it is very difficult to devise definitive criteria for the diagnosis of vitamin B12 or folate deficiency, and this is why it is important for your symptoms to be taken into account when a diagnosis is made.

• #19 Testing for Pernicious Anaemia | Pernicious Anaemia Society

  https://pernicious-anaemia-society.org/articles/testing-for-pernicious-anaemia/

  Definitive cut-off points to define clinical and subclinical deficiency states are not possible, given the variety of methodologies used and technical issues, and local reference ranges should be established. […] The NICE Guideline states: Less than 180 ng/l (133 pmol/l) : Confirmed vitamin B12 deficiency Between 180 and 350 ng/l (133 and 258 pmol/l) : Indeterminate test result possible vitamin B12 deficiency. Consider further testing in patients with symptoms. […] HoloTC seems to be a little better compared to serum B12, but a large indeterminate area exists. […] This test is not routinely carried out though it is a better indicator of B12 deficiency than serum B12 is. […] However, high MMA serum values are also found in people with impaired kidney function, impaired thyroid function, inherited methylmalonic aciduria and small-bowel overgrowth with bacteria.

• #20 Vitamin B12 deficiency – Symptoms, diagnosis and treatment | BMJ Best Practice

  https://bestpractice.bmj.com/topics/en-gb/822

  Vitamin B12 (cobalamin) deficiency classically presents with megaloblastic anaemia, but can also present with neurological and neuropsychiatric complaints. […] Early diagnosis is critical in preventing and halting the progression of neurological disorders such as peripheral neuropathy, sub-acute combined degeneration of the spinal cord, and dementia. […] Methylmalonic acid and homocysteine levels may help to diagnose vitamin B12 deficiency at an early, asymptomatic state. […] Cause of vitamin B12 deficiency should be searched for once a diagnosis is confirmed. […] Vitamin B12 level 258 picomols/L (350 picograms/mL) does not exclude vitamin B12 deficiency, particularly if pernicious anaemia is suspected. […] Key diagnostic factors include presence of risk factors, old age, and history of gastric surgery (gastrectomy, or bypass for obesity).

• #21 Vitamin B12 deficiency – Symptoms, diagnosis and treatment | BMJ Best Practice

  https://bestpractice.bmj.com/topics/en-gb/822

  1st investigations to order include FBC, peripheral blood smear, serum vitamin B12, and reticulocyte count. […] Investigations to consider include methylmalonic acid (MMA), homocysteine, holotranscobalamin (hTC), anti-intrinsic factor antibody (anti-IFAB), antiparietal cell (APC) antibody, and serum gastrin (fasting).

• #22 Vitamin B12 Deficiency: Recognition and Management | AAFP

  https://www.aafp.org/pubs/afp/issues/2017/0915/p384.html

  In patients with a normal or low-normal serum vitamin B12 level, complete blood count results demonstrating macrocytosis, or suspected clinical manifestations, a serum methylmalonic acid level is an appropriate next step and is a more direct measure of vitamin B12’s physiologic activity. […] Patients diagnosed with vitamin B12 deficiency whose history and physical examination do not suggest an obvious dietary or malabsorptive etiology should be tested for pernicious anemia with anti-intrinsic factor antibodies (positive predictive value = 95%), particularly if other autoimmune disorders are present.

• #23 Vitamin B12 Deficiency | AAFP

  https://www.aafp.org/pubs/afp/issues/2003/0301/p979.html

  Vitamin B12 (cobalamin) deficiency is a common cause of macrocytic anemia and has been implicated in a spectrum of neuropsychiatric disorders. […] Diagnosis of vitamin B12 deficiency is typically based on measurement of serum vitamin B12 levels; however, about 50 percent of patients with subclinical disease have normal B12 levels. A more sensitive method of screening for vitamin B12 deficiency is measurement of serum methylmalonic acid and homocysteine levels, which are increased early in vitamin B12 deficiency. […] The diagnosis of vitamin B12 deficiency has traditionally been based on low serum vitamin B12 levels, usually less than 200 pg per mL (150 pmol per L), along with clinical evidence of disease. However, studies indicate that older patients tend to present with neuropsychiatric disease in the absence of hematologic findings.

• #24 Vitamin B12 Deficiency | AAFP

  https://www.aafp.org/pubs/afp/issues/2003/0301/p979.html

  Furthermore, measurements of metabolites such as methylmalonic acid and homocysteine have been shown to be more sensitive in the diagnosis of vitamin B12 deficiency than measurement of serum B12 levels alone. […] In a large study of 406 patients with known vitamin B12 deficiency, 98.4 percent had elevated serum methylmalonic acid levels, and 95.9 percent had elevated serum homocysteine levels (defined as three standard deviations above the mean). […] This finding suggests that methylmalonic acid and homocysteine levels can be early markers for tissue vitamin B12 deficiency, even before hematologic manifestations occur. […] Use of methylmalonic acid and homocysteine levels in the diagnosis of vitamin B12 deficiency has led to some surprising findings. […] This observation suggests that use of a low serum vitamin B12 level as the sole means of diagnosis may miss up to one half of patients with actual tissue B12 deficiency. […] An algorithm for the diagnosis of vitamin B12 deficiency is provided in Figure 3.

• #25 Vitamin B12 Deficiency

  https://labtestsonline.org.uk/conditions/vitamin-b12-and-folate-deficiency

  Total B12. If low, a deficiency is indicated, but it does not identify the cause. […] Active B12. This accounts for about a quarter of the B12 circulating in blood. […] Folate. Either serum or RBC folate may be tested. […] Seldom but sometimes used to diagnose B12 and folate deficiency: Methylmalonic Acid (MMA). A blood or urine test, sometimes used to help detect mild or early B12 deficiency, or to exclude true B12 deficiency in cases of a misleadingly low laboratory B12 result. […] Requested to help determine the cause of a B12 deficiency: Schilling Test. Once frequently used to confirm a diagnosis of pernicious anaemia. […] Intrinsic Factor (Blocking) Antibody. A protein that prevents B12 from binding to intrinsic factor. […] Treatment for B12 and folate deficiencies frequently involves long-term or lifetime supplementation. Patients who lack intrinsic factor or have conditions causing general malabsorption usually require B12 injections. […] If a patient is deficient in both B12 and folate, he or she will require replenishment of both.

• #26 Differential Diagnosis of Megaloblastic Anemia: B12 Deficiency and Folate Deficiency

  https://www.labce.com/spg3652445_differential_diagnosis_of_megaloblastic_anemia_b12.aspx?srsltid=AfmBOopBWrOVpywSyiIL0I-1tyiFKVmn5kq4NWog5CVsyo7Rm3mighwo

  After a probable diagnosis of megaloblastic anemia is established, specific laboratory tests are needed to determine the cause. […] Table 5 displays the specific tests and results to determine Vitamin B12 deficiency versus Folate deficiency. […] These tests are useful because Vitamin B12 is required for methylmalonic acid (MMA) to be converted to succinyl-CoA, and in combination with folic acid, for homocysteine (HC) to be converted to methionine. […] Thus, MMA and HC are elevated. MMA and HC are further useful for the differential diagnosis of B12 and folate deficiency; in B12 deficiency, both are elevated, whereas in folate deficiency, usually only HC is elevated. […] If a diagnosis of B12 or folate deficiency is established, the next step is to determine the reason.

• #27 Vitamin B12 or folate deficiency anaemia – Diagnosis | Health Information from Mileusnic Chemist

  https://mileusnicchemist.co.uk/nhs_conditions_vitamin-b12-or-folate-deficiency-anaemia_diagnosis

  A diagnosis of vitamin B12 or folate deficiency anaemia can often be made by a GP based on your symptoms and the results of blood tests. […] Different types of blood tests can be carried out to help identify people with a possible vitamin B12 or folate deficiency. […] These tests check: whether you have a lower level of haemoglobin (a substance that transports oxygen) than normal, whether your red blood cells are larger than normal, the level of vitamin B12 in your blood, the level of folate in your blood. […] It’s also important for your symptoms to be taken into account when a diagnosis is made. […] If your symptoms and blood test results suggest a vitamin B12 or folate deficiency, your GP may arrange further tests. […] If the cause can be identified, it’ll help to determine the most appropriate treatment.

• #28 Vitamin deficiency anemia – Diagnosis & treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/vitamin-deficiency-anemia/diagnosis-treatment/drc-20355031

  To help diagnose vitamin deficiency anemias, you might have blood tests that check for: […] The amount of vitamin B-12 and folate in the blood. […] The presence of antibodies to intrinsic factor, which indicates pernicious anemia.

• #29 Pernicious anemia – Wikipedia

  https://en.wikipedia.org/wiki/Pernicious_anemia

  Pernicious anemia refers to a type of vitamin B12 deficiency anemia that results from lack of intrinsic factor. […] When suspected, diagnosis is made by blood tests initially a complete blood count, and occasionally, bone marrow tests. […] Blood tests may show fewer but larger red blood cells, low numbers of young red blood cells, low levels of vitamin B12, and antibodies to intrinsic factor. […] Diagnosis is not always straightforward and can be challenging. […] Vitamin B12 serum levels are used to detect its deficiency, but do not distinguish its causes. […] Low levels of serum vitamin B12 may be caused by other factors than B12 deficiency, such as folate deficiency, pregnancy, oral contraceptive use, haptocorrin deficiency, and myeloma. […] The presence of antibodies to gastric parietal cells and intrinsic factor is common in PA.

• #30 Vitamin B12 Deficiency – Nutritional Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/nutritional-disorders/vitamin-deficiency-dependency-and-toxicity/vitamin-b12-deficiency

  Dietary vitamin B12 deficiency usually results from inadequate absorption, but deficiency can develop in vegans who do not take vitamin supplements. […] Diagnosis is usually made by measuring serum vitamin B12 levels. […] Diagnosis of vitamin B12 deficiency is based on CBC and vitamin B12 and folate levels. […] A vitamin B12 level 200 pg/mL (145 pmol/L) indicates vitamin B12 deficiency. […] The folate level is measured because vitamin B12 deficiency must be differentiated from folate deficiency as a cause of megaloblastic anemia; folate supplementation can mask vitamin B12 deficiency and may alleviate megaloblastic anemia but allow the neurologic deficits to progress or even accelerate. […] Complete blood count (CBC) and vitamin B12 and folate levels. […] Sometimes methylmalonic acid levels or Schilling test.

• #31 Vitamin B12 | Pathology Tests Explained

  https://pathologytestsexplained.org.au/ptests-pro.php?q=Vitamin%20B12

  Vitamin B12 and folate are usually measured when a full blood count and/or blood film, done routinely or as part of an evaluation of anaemia, indicates decreased haemoglobin concentration and/or the presence of large red cells. […] The doctor is looking for vitamin B12 and/or folate deficiencies. If a symptomatic patient has decreased concentrations of vitamin B12 and/or folate, then it is likely that they have some degree of deficiency. […] If a patient is deficient in both vitamin B12 and folate, but only takes folic acid supplements, the vitamin B12 deficiency may be masked. The anaemia associated with both may be resolved, but the underlying neuropathy (nerve damage) will persist.

• #32 Vitamin B12 & Folate

  https://labtestsonline.org.uk/tests/vitamin-b12-and-folate

  Vitamin B12 and folate are primarily requested to help diagnose the cause of macrocytic anaemia. […] When a person, especially an elderly person, exhibits mental or behavioural changes such as irritability, confusion, depression and/or paranoia, vitamin B12 may be requested to help diagnose the underlying cause. […] The doctor is looking for vitamin B12 and/or folate deficiency. If a symptomatic patient has decreased concentrations of vitamin B12 and/or folate, then it is likely that he has some degree of deficiency. […] If a patient is deficient in both vitamin B12 and folate, but only takes folic acid supplements, the vitamin B12 deficiency may be masked. […] In the past the Schilling test was used to confirm a diagnosis of pernicious anaemia by demonstrating abnormal B12 absorption in the small intestine however it is no longer available.

• #33 B12 and Folate Testing – GP Gateway

  https://www.coventryrugbygpgateway.nhs.uk/pages/b12-and-folate-testing/

  A diagnosis of vitamin B12 or folate deficiency anaemia can often be made based on symptoms and the results of blood tests. […] Care should be taken when prescribing folic acid alone If folic acid is given to a patient who is actually b12 deficient, this may precipitate irreversible neurological complications.

• #34 Vitamin B12 deficiency – Wikipedia

  https://en.wikipedia.org/wiki/Vitamin_B12_deficiency

  The presence of antibodies to gastric parietal cells and intrinsic factor may indicate pernicious anemia. […] Deficiency can develop without anemia or within normal vitamin B12 levels, leading to a methylmalonic acid or homocysteine assay. […] Neuropsychiatric symptoms can precede hematological signs and are often the presenting manifestation of B12 deficiency. […] Anemia can be prevented or masked by folic acid in which activate tetrahydrofolate (THF) needed for DNA synthesis.

• #35 Folate and vitamin B12: friendly or enemy nutrients for the elderly* | Proceedings of the Nutrition Society | Cambridge Core

  https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/folate-and-vitamin-b12-friendly-or-enemy-nutrients-for-the-elderly/D8C38CD6D49977957C5B098623459519

  In the UK vitamin B12 deficiency occurs in approximately 20% of adults aged 65 years. This incidence is significantly higher than that among the general population. […] The incidence of, and the criteria for diagnosis of, deficiency have drawn much attention recently in the wake of the implementation of folic acid fortification of flour in the USA. […] It is argued that consuming additional folic acid (as synthetic pteroylglutamic acid) from fortified foods increases the risk of masking megaloblastic anaemia caused by vitamin B12 deficiency. […] Is serum vitamin B12 alone adequate to confirm vitamin B12 deficiency or should other diagnostic markers be used routinely in clinical practice? […] Detection and treatment of the early stages of cobalamin deficiency is important, particularly in patients with neuropsychiatric symptoms because they may fail to respond if therapy is delayed.

• #36 Folate and vitamin B12: friendly or enemy nutrients for the elderly* | Proceedings of the Nutrition Society | Cambridge Core

  https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/folate-and-vitamin-b12-friendly-or-enemy-nutrients-for-the-elderly/D8C38CD6D49977957C5B098623459519

  All patients with unexplained anaemia and/or unexplained neuropsychiatric symptoms should ideally be examined for cobalamin deficiency, because vitamin B12 deficiency can result in neurological symptoms without haematological abnormalities. […] The early stages of vitamin B12 deficiency will not lead to macrocytosis or anaemia, because biochemical vitamin B12 deficit precedes overt clinical deficiency with macro-ovalocytes and falling Hb levels. […] The sensitivity of mean corpuscular volume (MCV) to detect vitamin B12 deficiency is low, and many patients with vitamin B12 deficiency will remain unnoticed when the MCV is used to decide whether further evaluation is necessary. […] Cobalamin deficiency can take years to develop. Consequently, the clinical symptoms of classical cobalamin deficiency, i.e. of severe megaloblastic anaemia combined with neuropsychiatric symptoms, are rarely seen today.

• #37 Folate and vitamin B12: friendly or enemy nutrients for the elderly* | Proceedings of the Nutrition Society | Cambridge Core

  https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/folate-and-vitamin-b12-friendly-or-enemy-nutrients-for-the-elderly/D8C38CD6D49977957C5B098623459519

  The concept that patients suffering from cobalamin deficiency may have neuropsychiatric symptoms without macrocytosis or anaemia was not widely accepted until relatively recently. […] Thus, it has been realized that neuropsychiatric illness may be the only symptom of cobalamin deficiency and, importantly, the neurological symptoms are considered of most concern because they may fail to remit on therapy. […] It is now commonly accepted that there are five stages of vitamin B12 deficiency that between them encompass the range from normal status to severe deficiency. […] The use of any marker as a diagnostic test for the detection or exclusion of vitamin B12 deficiency is only useful if its diagnostic accuracy is sufficiently high. […] MCV should not be relied on when screening for vitamin B12 deficiency.

• #38 Diagnosis of Pernicious Anaemia | Pernicious Anaemia Society

  https://pernicious-anaemia-society.org/diagnosis/

  The clinical picture is the most important factor in assessing the significance of test results assessing cobalamin status since there is no gold standard test to define deficiency. […] Do not delay vitamin B12 replacement while waiting for the test results of people with suspected megaloblastic anaemia and neurological symptoms, especially symptoms related to sub-acute combined degeneration of the spinal cord. […] In the presence of discordance between the test result and strong clinical features of deficiency, treatment should not be delayed to avoid neurological impairment.

• #39 Vitamin B12 Deficiency: Recognition and Management | AAFP

  https://www.aafp.org/pubs/afp/issues/2017/0915/p384.html

  Vitamin B12 deficiency is a common cause of megaloblastic anemia, various neuropsychiatric symptoms, and other clinical manifestations. Screening average-risk adults for vitamin B12 deficiency is not recommended. Screening may be warranted in patients with one or more risk factors, such as gastric or small intestine resections, inflammatory bowel disease, use of metformin for more than four months, use of proton pump inhibitors or histamine H2 blockers for more than 12 months, vegans or strict vegetarians, and adults older than 75 years. Initial laboratory assessment should include a complete blood count and serum vitamin B12 level. Measurement of serum methylmalonic acid should be used to confirm deficiency in asymptomatic high-risk patients with low-normal levels of vitamin B12. […] The recommended laboratory evaluation for patients with suspected vitamin B12 deficiency includes a complete blood count and serum vitamin B12 level. A level of less than 150 pg per mL (111 pmol per L) is diagnostic for deficiency.

• #40 Cobalamin (vitamin B12) and Folate Deficiency – Province of British Columbia

  https://www2.gov.bc.ca/gov/content/health/practitioner-professional-resources/bc-guidelines/vitamin-b12

  This guideline covers the primary care investigation and management of cobalamin (vitamin B12 or simply B12) and folate deficiency in adults. […] Routine B12 screening and testing in asymptomatic patients is not supported by evidence. […] Folate testing is rarely indicated but may be available via consultation with the laboratory medicine physician or scientist. […] No studies evaluating the clinical utility of B12 testing in people with suspected B12 deficiency. […] No studies evaluating the cost-effectiveness of B12 testing in people with suspected B12 deficiency. […] No evidence-based guidelines regarding the use of B12 testing in people with suspected B12 deficiency. […] In a clinically symptomatic patient with specific features of B12 deficiency, order a B12 test. […] Asymptomatic: In asymptomatic patients with risk factors consider supplementation in lieu of testing.

• #41 Vitamin B12 Deficiency: Signs, Causes and Treatments | Ada

  https://ada.com/conditions/vitamin-b12-deficiency/

  Vitamin B12 deficiency occurs when there are inadequate levels of the vitamin B12 in the body. This important vitamin is necessary for the production of red blood cells and the healthy functioning of the nervous system. […] A lack of vitamin B12 can cause anemia and other health problems. Anemia is a condition where the body either cannot make enough healthy red blood cells or cannot produce enough of the substance hemoglobin that allows red blood cells to transport oxygen around the body. […] For this reason, a doctor will typically examine the levels of folate in blood tests when checking for vitamin B12 deficiency. Taking a lot of folic acid can mask the symptoms of a vitamin B12 deficiency, so in cases where folate deficiency is suspected, a doctor will usually test for vitamin B12 deficiency before prescribing medication.

• #42 Pernicious Anaemia and B12 Deficiency | Doctor

  https://patient.info/doctor/pernicious-anaemia-and-b12-deficiency

  Pernicious anaemia is an autoimmune gastritis that causes atrophy of all layers of both the body and fundus of the stomach, and loss of normal gastric glands, mucosal architecture, and parietal and chief cells, leading to atrophic gastritis. This atrophy reduces the number of parietal cells which secrete intrinsic factor (IF). […] IF is essential for the absorption of vitamin B12. Antibodies to IF are very specific for pernicious anaemia, but only present in 50% to 70% of people with the condition. […] The resultant malabsorption of vitamin B12 leads to vitamin B12 deficiency, which ultimately leads to pernicious anaemia. […] The diagnosis of vitamin B12 deficiency should not be excluded solely on the absence of either anaemia or macrocytosis. Vitamin B12 deficiency can be associated with mental health problems, including symptoms of depression, anxiety or psychosis.

• #43 Practice Nursing – Understanding vitamin B12 and folate deficiency

  https://www.practicenursing.com/content/clinical/understanding-vitamin-b12-and-folate-deficiency/

  Vitamin B12 and folate deficiencies are common and have a big impact on sufferers’ lives. […] Diagnosis can often be problematic as many of the symptoms patients present with are shared with other conditions and can easily be attributed to other causes. […] Diagnosis can often be problematic as many of the symptoms patients present with are shared with other conditions and can easily be attributed to other causes. […] Diagnosis can be easily overlooked, but correct treatment has the ability to transform sufferer’s lives in terms of improving energy levels and preventing further complications. […] This article aims to give practice nurses and nurse prescribers a better understanding of both conditions, and more confidence in diagnosing and treating their patients.

• #44 Pernicious anaemia: recognition, diagnosis and management – The Pharmaceutical Journal

  https://pharmaceutical-journal.com/article/ld/pernicious-anaemia-recognition-diagnosis-and-management

  Vitamin B12 deficiency, including pernicious anaemia, is commonly encountered in primary care and pharmacists should be able to identify those people most at risk, know the common symptoms and ensure that patients receive adequate and personalised treatment. […] For patients presenting with clinical symptoms of vitamin B12 deficiency, current guidelines recommend testing serum vitamin B12 levels alongside a full blood count and folate levels. […] Diagnosis can be challenging because the serum test is not always conclusive. […] If pernicious anaemia is suspected, a test for anti-intrinsic factor antibody should also be undertaken. […] Owing to the insidious onset of symptoms and limitations in diagnostic testing, many patients experience delays in diagnosis, with studies indicating that 38% of patients wait five years or more before diagnosis. […] Diagnosis and management of pernicious anaemia is currently imprecise, with many unanswered questions and a lack of consistency in practice.

• #45 Case Study: Vitamin B12 Deficiency – ASCLS

  https://ascls.org/case-study-vitamin-b12-deficiency/

  Based on the clinical presentation and laboratory findings, a diagnosis of psychomotor regression due to B12 deficiency was made. […] Common diagnostic lab tests for B12 deficiency typically begin with serum B12 measurement and a complete blood count (CBC). Low B12 levels and evidence of megaloblastic anemia (decreased RBC, Hgb, Hct, WBC, platelet count, increased MCV, large oval RBCs and hypersegmented neutrophils) indicate B12 deficiency. […] Diagnosis of B12 deficiency can be complicated since symptoms may be vague and lab test results can be equivocal.

• #46 Diagnosis, Treatment and Long-Term Management of Vitamin B12 Deficiency in Adults: A Delphi Expert Consensus

  https://www.mdpi.com/2077-0383/13/8/2176

  Diagnosis, Treatment and Long-Term Management of Vitamin B12 Deficiency in Adults: A Delphi Expert Consensus […] Background/Objectives: Vitamin B12 deficiency can cause variable symptoms, which may be irreversible if not diagnosed and treated in a timely manner. We aimed to develop a widely accepted expert consensus to guide the practice of diagnosing and treating B12 deficiency. […] Recognition of clinical symptoms should receive the highest priority in establishing the diagnosis. There is agreement that the serum B12 concentration is useful as a screening marker and methylmalonic acid or homocysteine can support the diagnosis. […] There is a consensus that clinical symptoms need to receive more attention in establishing the diagnosis of B12 deficiency. B12 laboratory markers can support the diagnosis. […] The algorithm for diagnosing vitamin B12 deficiency and its causes was agreed upon among the panelists. In people with symptoms suggesting vitamin B12 deficiency, the general practitioner can collect information on medical history, perform physical examinations, and perform basic laboratory tests such as full blood cell count and serum B12 concentration. […] The panelists agreed that the delay in the diagnosis of vitamin B12 deficiency may be explained by barriers such as the variability of symptoms, low doctor awareness of the disease, not paying attention to the patient’s symptoms, and limited access to modern laboratory markers. […] The experts agreed that food-cobalamin malabsorption may cause vitamin B12 deficiency in elderly people even if the dietary intake of B12 is adequate and the person has no gastrointestinal disorders. […] In context of the B12 diagnostic work-up, folate and iron status should also be assessed.

• #47

• #48 Vitamin B12 Deficiency – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK441923/

  In patients with a deficiency in intrinsic factors, either due to pernicious anemia or gastric bypass surgery, a parenteral dose of B12 is recommended, as oral B12 will not be fully absorbed due to the lack of intrinsic factors. […] The differential diagnosis includes the following: Lead toxicity, Syphilis, HIV myelopathy, Multiple sclerosis. […] For patients who are promptly treated with vitamin B12, the prognosis is good.

• #49 Folate Deficiency Anemia: Symptoms, Causes & Treatment

  https://my.clevelandclinic.org/health/diseases/24196-folate-deficiency-anemia

  Your provider will also check your blood folate levels and evaluate the levels using this scale: […] Treatment for folate deficiency anemia is usually successful. Within several months of taking or receiving vitamin B9 supplements, most people start producing healthy red blood cells again and their symptoms improve.

• #50 Pernicious Anaemia and B12 Deficiency | Doctor

  https://patient.info/doctor/pernicious-anaemia-and-b12-deficiency

  If vitamin B12 deficiency is diagnosed in pregnancy or during breastfeeding and autoimmune gastritis is the suspected cause, offer an anti-intrinsic factor antibody test if the criteria above is met and start treatment with intramuscular vitamin B12 replacement. […] People with pernicious anaemia are at increased risk of developing gastric cancer and there is an association with other autoimmune diseases, including primary hypothyroidism, thyrotoxicosis, Hashimoto’s thyroiditis, Addison’s disease, type 1 diabetes, hypoparathyroidism and vitiligo. […] Response to treatment of vitamin B12 deficiency can vary and depends on the cause of the vitamin B12 deficiency. Symptoms may start to improve within 2 weeks, but this may take up to 3 months. […] Lifelong intramuscular vitamin B12 replacement if: autoimmune gastritis is the cause, or suspected cause, of vitamin B12 deficiency, or they have had a total gastrectomy, or a complete terminal ileal resection. […] If vitamin B12 deficiency is diagnosed in pregnancy or during breastfeeding and autoimmune gastritis is the suspected cause, offer an anti-intrinsic factor antibody test if the criteria above is met and start treatment with intramuscular vitamin B12 replacement.

• #51 3.7 Vitamin B12 and Folate Deficiency Anemia – Health Alterations

  https://wtcs.pressbooks.pub/healthalts/chapter/3-7-vitamin-b12-and-folate-deficiency-anemia/

  Medical Interventions for vitamin B12 deficiency depend on the cause, as well as the severity of the disorder. Common medical treatments include Vitamin B12 Supplements (Cyanocobalamin) and Routine Monitoring of Vitamin B12 Levels. […] Folate deficiency is treated with oral or parenteral administration of folic acid.

• #52 Vitamin B12 and Serum Folate

  https://www.gloshospitals.nhs.uk/our-services/services-we-offer/pathology/tests-and-investigations/vitamin-b12-and-serum-folate/

  Vitamin B12 and serum folate are no longer performed on elderly patients in the acute setting unless there is a specific indication e.g. macrocytosis +/- anaemia, (pan)cytopenia, or blood film report comment. […] The common causes of deficiency are inadequate diet, malabsorption, anti-folate drugs (especially anticonvulsants) and occasionally in association with any disease that causes increase cell turnover, e.g. exfoliation. […] Testing should be restricted to those with a suspected vitamin B12 deficiency (macrocytosis, anaemia, neurological deficit, glossitis or clinical condition known to cause B12 deficiency) and should not be used as a screening test. […] When the B12 level is less than 150 pg/mL a presumptive diagnosis of B12 deficiency is made. […] If there is no response, it is likely that the patient is not B12 deficient and other causes of the clinical problem must be sought.

• #53 Identify Vitamin B12 and Folate Deficiency Symptoms

  https://www.medicinesteam.co.uk/post/vitamin-b12-and-folate-deficiency-anemia

  Treatment varies depending on the cause and severity of the deficiency. […] Recovery time varies, but many people begin to feel better within a few weeks of starting treatment. Full recovery can take several months, depending on the severity of the deficiency and the treatment method used. […] Ignoring vitamin B12 and folate deficiencies can lead to serious health issues. […] While deficiencies themselves are not direct indicators of cancer, they can be associated with certain types of cancer. For instance, some gastrointestinal cancers can affect nutrient absorption, leading to deficiencies. It’s important to consult a healthcare professional if you suspect a deficiency, as they can help determine the underlying cause and appropriate treatment.

• #54 Vitamin B12 Deficiency: Signs, Causes and Treatments | Ada

  https://ada.com/conditions/vitamin-b12-deficiency/

  A doctor will typically take the persons medical history and perform a physical examination. If they suspect a vitamin B12 deficiency, they will usually request blood tests to be done. These tests can measure levels of vitamin B12 and folic acid, as well as the size and concentration of hemoglobin within the persons red blood cells. […] Some people experience symptoms of vitamin B12 deficiency despite their blood tests indicating normal levels. The test measures the total amount of the vitamin in the blood, but not all of it can necessarily be used by the body. […] If vitamin B12 deficiency is suspected or confirmed, further tests may be required to identify the cause. This will help to determine the recommended course of treatment. […] Treatment will depend on the reasons for the vitamin B12 deficiency. In most cases, having injections or taking a prescribed oral supplement will be sufficient to treat the condition. […] A vitamin B12 deficiency is easy to treat and complications are rare. However, in some cases, particularly where there has been a severe or prolonged deficiency, nerve damage may be permanent and irreversible.

• #55 Severe Vitamin B12 And Folate Deficiency In A 14-Year-Old Girl: A Case Report Of Presentation With Pancytopenia

  https://acquaintpublications.com/article/severe-vitamin-b12-and-folate-deficiency-in-a-14-year-old-girl-a-case-report-of-presentation-with-pancytopenia

  Severe Vitamin B12 And Folate Deficiency In A 14-Year-Old Girl: A Case Report Of Presentation With Pancytopenia […] Further tests confirmed powerful vitamin B12 and folate deficiency. […] This case report discusses the diagnosis and management of severe vitamin B12 and folate deficiency in children and highlights the potential for similar presentations to aplastic anemia and hemolysis. […] After ruling out other causes, these findings were attributed to severe vitamin B12 and folate deficiency. […] A study of 201 patients with documented cobalamin deficiency revealed that hematological signs, including macrocytosis and hyper-segmented neutrophils, are often present, and a high index of suspicion is required for diagnosis. […] Physicians should have a high index of suspicion for megaloblastic anemia in children with a history of dietary restrictions and present with hematological abnormalities. A thorough dietary history and early diagnosis can prevent severe complications, and effective management can ensure an excellent prognosis.

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