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Malabsorption of Vitamin B12

Malabsorption of Vitamin B12 (cyanocobalamin)


  • Possibly such malabsorption may also be present in many of those vegans developing overt vitamin-B12 deficiency in whom Schilling test findings have been normal.[ncbi.nlm.nih.gov]
  • Although inherited the defect was apparently not present at birth. A third child had less severe vitamin B12 malabsorption, was not vitamin B12 deficient and had no proteinuria.[ncbi.nlm.nih.gov]
  • A review of the history and literature of this diagnostic test using protein bound vitamin B12 is also presented.[ncbi.nlm.nih.gov]
  • Known causes of vitamin B 12 malabsorption such as intrinsic-factor deficiency, anti-intrinsic-factor antibodies, ileal disease and bacterial overgrowth were not present.[nejm.org]
  • Otherwise, no hitherto known causes of the reduced vitamin B 12 absorption could be found, in particular no other malabsorption symptoms were present.[onlinelibrary.wiley.com]
  • The outcome is malnutrition. Malnutrition may also be caused by inadequate diet with or without malabsorption. See also the separate Malnutrition article.[patient.info]
  • Deficiency may be caused by malabsorption, malnutrition, or an increased demand. The most common underlying cause of vitamin B 12 deficiency is pernicious anemia, an autoimmune disorder characterized by the absence of intrinsic factor (IF).[amboss.com]
  • Peripheral neuropathy may occur as a result of malnutrition, for which there are many causes including poor nutrition caused by an unbalanced diet and/or alcoholism.[foundationforpn.org]
  • You may have anemia, malnutrition, low blood pressure, weight loss, or muscle wasting. Malabsorption may affect people based on age or gender. For instance, women may stop menstruating, and children may not grow properly.[healthline.com]
  • Familial selective vitamin B 12 malabsorption (Imerslund-Grasbeck syndrome) in a pool of Turkish patients. Pediatr Hematol Oncol 1995 ; 12 : 19 -28. Altay C, Cetin M. Oral treatment in selective vitamin B 12 malabsorption.[clinchem.aaccjnls.org]
  • One Turkish study compared the vitamin B12 levels of patients who sought treatment in the ER for dizziness with those of 100 healthy volunteers. The result: Those dizzy patients had 40% less B12 than the volunteers. Your skin looks pale.[prevention.com]
Down Syndrome
  • A 3 year old girl with Down's syndrome became lethargic and withdrawn, and investigations showed a specific malabsorption of vitamin B12 without proteinuria.[ncbi.nlm.nih.gov]
  • Funding and Disclosures Studies carried out in the Adult Clinical Research Center and supported by a grant (FR 00229) from the Division of Research Facilities and Resources and by a grant (AM05375) from the National Institute of Arthritis and Metabolic[nejm.org]
  • Because celiac disease causes damage and, over time, the destruction of villi, people with this condition often suffer from malabsorption of essential vitamins, increasing the risk of vitamin deficiency anemia, fatigue, bone pain, arthritis and peripheral[livestrong.com]
  • If you suffer from immune system dysfunctions such as rheumatoid arthritis, lupus, or celiac disease, then it’s important to get your vitamin B12 levels checked regularly.[blog.vitasciences.com]
  • The classic hematological abnormalities encountered include aregenerative macrocytary anemia and other less common, though more severe, hematological abnormalities as: intramedullar hemolysis, thrombopenic purpura, myelodysplasia, medullar aplasia, early-stage[omicsonline.org]
  • A 3 year old girl with Down's syndrome became lethargic and withdrawn, and investigations showed a specific malabsorption of vitamin B12 without proteinuria.[ncbi.nlm.nih.gov]
Cognitive Disorder
  • Clinical features of food-cobalamin malabsorption syndrome Mean age years 76 8 Sex ratio (women/men) 2 Symptomatic patients Clinically 70% Biologically 76% Main clinical manifestations Sensitive polyneuropathy 45% Cognitive disorders 23% Asthenia 21%[omicsonline.org]


Abnormal Schilling Test
  • Despite the frequency of abnormal Schilling tests, vitamin B12 deficiency is very rare in cases of exocrine pancreatic dysfunction, in adults as well as in children with cystic fibrosis.[ncbi.nlm.nih.gov]
  • Eight subjects (73%), including these 3 subjects plus 5 others with normal vitamin B 12 levels, had abnormal Schilling test results.[jamanetwork.com]
Macrocytic Anemia
  • Megaloblastic macrocytic anemia Antony AC. Megaloblastic anemias. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 7th ed. Philadelphia, PA: Elsevier; 2018:chap 39. Bunn HF. Approach to the anemias.[medlineplus.gov]
  • anemia Folate deficiency Myelodysplastic syndrome Starting folate treatment before excluding vitamin B 12 deficiency may correct anemia, but could worsen neuropathy![amboss.com]
  • The opposite of Macrocytic Anemia is Iron Deficiency Anemia, technically called, “Microcytic Anemia” micro meaning little.[health-boundaries.com]
  • Vitamin B 12 deficiency is one of the most common causes of macrocytic anemia [ 3, 4 ]. If it is not treated, anemia symptoms and neurological disturbances resulting in spinal cord and cerebral cortex demyelination may emerge [ 5 ].[intechopen.com]
  • Patient Information Handout Vitamin B 12 (cobalamin) deficiency is a common cause of macrocytic anemia and has been implicated in a spectrum of neuropsychiatric disorders.[aafp.org]
Giardia Lamblia
  • Jameson JE: Notes on cases of chronic diarrhoea and vague ill health, apparently due to the flagellate Giardia lamblia . J R Army Med Corps 77:320–323, 1941 Google Scholar 7. Fraser JF, Taylor R: Diarrhoea due to Giardia lamblia .[link.springer.com]
  • In addition, as you will see below, other digestive infections such as tapeworm and Giardia lamblia can also result in a reductino in B12 absorption.[h-pylori-symptoms.com]


  • Defective absorption was also found in six patients with an adequate dietary intake of vitamin B12, normal Schilling test results, low serum vitamin concentrations, and tissue changes responding to treatment with vitamin B12.[ncbi.nlm.nih.gov]
  • Lane LA, Rojas-Fernandez C (2002) Treatment of vitamin b(12)-deficiency anemia: oral versus parenteral therapy. Ann Pharmacother 36: 1268-1272.[omicsonline.org]
  • Central Hospital, Næstved, Denmark Search for more papers by this author Herlufsvænge 18, Næstved Denmark Abstract A 44-year-old woman underwent extirpation of a reticulum cell sarcoma in the right anxilla 10 years previously, followed by local roentgen treatment[onlinelibrary.wiley.com]
  • Replacement treatment with oral B12 1,000 micrograms/daily was instituted. RESULTS: Reticulocytosis was observed on the third day of treatment, which was followed by a gradual increase in Hb level to 12 g/dL in 3 weeks.[ncbi.nlm.nih.gov]
  • Oral treatment in selective vitamin B 12 malabsorption. J Pediatr Hematol Oncol 1997 ; 19 : 245 -246. Altay C, Cetin M. Vitamin B 12 absorption test and oral treatment in 14 children with selective vitamin B 12 malabsorption.[clinchem.aaccjnls.org]


  • Prospective parents with a family history of the disorder may benefit from getting genetically tested and seeking genetic counselling With sustained treatment, the prognosis of Imerslund-Gräsbeck Syndrome is excellent.[dovemed.com]
  • Prognosis Prognosis is good. Without treatment, neurological and hematopoietic complications can occur that can also be fatal. The documents contained in this web site are presented for information purposes only.[orpha.net]
  • […] in the first week Neurologic symptoms improve within 6 weeks to 3 months Anemia , Leukopenia , MCV and Thrombocytopenia improve within 2 months Monitor Serum Potassium levels while replacing Vitamin B12 Hypokalemia occurs as hematopoiesis increases Prognosis[fpnotebook.com]
  • Other areas of interest include identifying new biomarkers that can be used for diagnosis and prognosis of liver disease, understanding mitochondrial oxidative stress in Alzheimers disease and gastrointestinal dysfunction in autism. Dr.[books.google.de]
  • […] nutritional plan, including foods high in vitamin B12 (such as meat, milk, cheese, and eggs) and folic acid (leafy, green vegetables, citrus fruits, and fortified cereals) foods high in the other B vitamins need to keep an accurate dietary history that the prognosis[quizlet.com]


  • The etiology of these syndromes is not known, but evidence for a hereditary predisposition as well as environmental factors has been documented.[annals.org]
  • Besides the aforementioned manifestations, those related to the age of the patient or the etiology of malabsorption should also be considered.[omicsonline.org]
  • Etiology Patients have bi-allelic mutations in the GIF gene on chromosome 11 encoding the gastric Intrinsic Factor (IF), a protein necessary for the absorption of vitamin B12.[orpha.net]
  • Causes The etiological factors leading to a deficiency of vitamin B12 may be due to deficit of the vitamin in the diet, impaired absorption of the vitamin because of malabsorption syndromes, and various miscellaneous gastrointestinal pathologies.[news-medical.net]
  • Etiology Malabsorption Intrinsic factor Pernicious anemia : most common cause of vitamin B 12 deficiency Atrophic gastritis (e.g., secondary to H. pylori infection) Gastrectomy Reduced uptake of IF- vitamin B 12 complex : e.g., Crohn's disease ;, celiac[amboss.com]


  • The goal of this study is to review epidemiological studies related to vitamin B12 deficiency and to point out the importance of identifying and treating it. Keywords epidemiology vitamin B12 anemia deficiency nutrition 1.[intechopen.com]
  • Summary Epidemiology The incidence and prevalence of IFD are unknown. Fewer than 100 cases have been reported in the literature and fewer than 50 cases have been confirmed molecularly.[orpha.net]
  • ., Heymsfield, SB, Ross, RR, Garry, PJ, and Lindeman, RD Epidemiology of sarcopenia among the elderly in New Mexico. ‎ Seite 149 - Kumar R, Riggs BL: Impaired vitamin D metabolism with aging in women.[books.google.de]
  • Vitamin B12 Deficiency , Pernicious Anemia, B12 Deficiency, Cobalamin Deficiency, Cyanocobalamin Deficiency Epidemiology Prevalence U.S.: 6% in patients under age 60 years (20% in those over age 60 years) Latin America: 40% Kenya: 70% East India: 70-80%[fpnotebook.com]
  • Galer BS, Gianas A, Jensen MP (2000) Painful diabetic polyneuropathy: epidemiology, pain description, and quality of life. Diabetes research and clinical practice 47: 123–128. View Article Google Scholar 23.[journals.plos.org]
Sex distribution
Age distribution


  • .: 6% in patients under age 60 years (20% in those over age 60 years) Latin America: 40% Kenya: 70% East India: 70-80% Pathophysiology See Vitamin B12 Symptoms may lag Vitamin B12 Deficiency for as many as 10 years until vast hepatic stores are exhausted[fpnotebook.com]
  • ., during pregnancy, breastfeeding, fish tapeworm ( Diphyllobothrium latum ) infections, and leukemia References: [1] Pathophysiology Dysfunctional biochemical reactions Physiological function : Vitamin B 12 is a water-soluble cofactor for enzymatic reactions[amboss.com]
  • Vitamin B 12 treatment must be continued for life unless the pathophysiologic mechanism for the deficiency is corrected. Infants of vegan mothers should receive supplemental vitamin B 12 from birth.[merckmanuals.com]
  • Complications, pathophysiology, and outcomes. Journal of Inherited Metabolic Disease 35: 103–114. Coelho D, Suormala T, Stucki M, et al. (2008) Gene identification for the cblD defect of vitamin B12 metabolism.[els.net]


  • A failure to degrade haptocorrin can prevent the binding of vitamin B12 to intrinsic factor.[ncbi.nlm.nih.gov]
  • Colchicine in vitro did not prevent vitamin B 12 binding to intrinsic factor or binding of this combination to guinea-pig ileal mucosa.[nejm.org]
  • Author information 1 National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA. ceh9@cdc.gov Abstract The incidence of neonatal vitamin B12 (cobalamin) deficiency because of maternal[ncbi.nlm.nih.gov]
  • If B12 deficiency is due to alcoholism, abstinence may prevent further impairment of B12 absorption. Nutritional Supplements Commonly 3 to 4 mcg/day of vitamin B12 prevents deficiency.[anapsid.org]
  • Prevention The best prevention is adequate dietary intake of B12 vitamin. When the problem is caused by malabsorption, it is necessary to supplement vitamin B12 in injection form.[health-tutor.com]

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