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Record Information
Creation Date2005-11-16 15:48:42 UTC
Update Date2013-07-24 17:50:11 UTC
Secondary Accession Numbers
  • HMDB14263
Metabolite Identification
Common NameCyanocobalamin
DescriptionCyanocobalamin (commonly known as Vitamin B12) is the most chemically complex of all the vitamins. Cyanocobalamin's structure is based on a corrin ring, which, although similar to the porphyrin ring found in heme, chlorophyll, and cytochrome, has two of the pyrrole rings directly bonded. The central metal ion is Co (cobalt). Cyanocobalamin cannot be made by plants or by animals, as the only type of organisms that have the enzymes required for the synthesis of cyanocobalamin are bacteria and archaea. Higher plants do not concentrate cyanocobalamin from the soil and so are a poor source of the substance as compared with animal tissues. Cyanocobalamin is naturally found in foods including meat (especially liver and shellfish), eggs, and milk products.
  1. Anacobin
  2. Berubigen
  3. Betalin 12 Crystalline
  4. Betaline-12
  5. Betolvex
  6. Bevidox
  7. Bevidox concentrate
  8. Biocobalamine
  9. Byladoce
  10. Cabadon m
  11. Cobadoce forte
  12. Cobalin
  13. Cobavite
  14. Copharvit 5000
  15. Covit
  16. Crystamin
  17. Crystamine
  18. Crystimin
  19. Crystwel
  20. Cyano-B12
  21. Cyanobalamin concentrate
  22. Cyanocob(III)alamin
  23. Cyanocobalamin (JP15/USP)
  24. Cyanocobalamine
  25. Cyanocobalmin
  26. Cycobemin
  27. Cycolamin
  28. Cykobemin
  29. Cykobeminet
  30. Cyomin
  31. Cyredin
  32. Cytacon
  33. Cytamen
  34. Cytobion
  35. Depinar
  36. Dicopac
  37. Dimethylbenzimidazoylcobamide
  38. Distivit
  39. Docemine
  40. Docibin
  41. Docivit
  42. Dodecabee
  43. Dodecavite
  44. Dodex
  45. Duodecibin
  46. Embiol
  47. Emociclina
  48. Eritrone
  49. Erycytol
  50. Erythrotin
  51. Euhaemon
  52. Extrinsic factor
  53. Factor II
  54. Fermin
  55. Fresmin
  56. Hemomin
  57. Hepagon
  58. Hepavis
  59. Hepcovite
  60. Hylugel plus
  61. Lactobacillus lactis dorner factor
  62. Macrabin
  63. Megabion
  64. Megalovel
  65. Milbedoce
  66. Millevit
  67. Nagravon
  68. Nascobal
  69. Nascobal (TN)
  70. Normocytin
  71. Novidroxin
  72. Pernaemon
  73. Pernaevit
  74. Pernipuron
  75. Plecyamin
  76. Poyamin
  77. Rebramin
  78. Redamina
  79. Redisol
  80. Rhodacryst
  81. Rubesol
  82. Rubramin
  83. Rubripca
  84. Rubrocitol
  85. Sytobex
  86. Vibalt
  87. Vibisone
  88. Virubra
  89. Vita-rubra
  90. Vitamin B12
  91. Vitamin B12 complex
  92. Vitamin B12 Preparation
  93. Vitarubin
  94. Vitral
Chemical FormulaC63H89CoN14O14P
Average Molecular Weight1356.3731
Monoisotopic Molecular Weight1355.575230332
IUPAC Name3-[(10S,12R,13S,17R,23R,24R,25R,30S,35S,36S,40S,41S,42R,46R)-30,35-bis(2-carbamoylethyl)-24,36,41-tris(carbamoylmethyl)-1-cyano-15,46-dihydroxy-12-(hydroxymethyl)-5,6,17,23,28,31,31,36,38,41,42-undecamethyl-15,20-dioxo-11,14,16-trioxa-2λ⁴,9,19,26,43λ⁴,44λ⁴,45λ⁴-heptaaza-15λ⁵-phospha-1-cobaltadodecacyclo[¹,³⁴.1²,⁹.1¹⁰,¹³.0¹,²⁶.0³,⁸.0²³,²⁷.0²⁵,⁴².0³²,⁴⁴.0³⁹,⁴³.0³⁷,⁴⁵]heptatetraconta-2(47),3,5,7,27,29(44),32,34(45),37,39(43)-decaen-40-yl]propanamide
Traditional Name3-[(10S,12R,13S,17R,23R,24R,25R,30S,35S,36S,40S,41S,42R,46R)-30,35-bis(2-carbamoylethyl)-24,36,41-tris(carbamoylmethyl)-1-cyano-15,46-dihydroxy-12-(hydroxymethyl)-5,6,17,23,28,31,31,36,38,41,42-undecamethyl-15,20-dioxo-11,14,16-trioxa-2λ⁴,9,19,26,43λ⁴,44λ
CAS Registry Number68-19-9
InChI Identifier
Chemical Taxonomy
KingdomOrganic Compounds
Super ClassAromatic Heteropolycyclic Compounds
ClassTetrapyrroles and Derivatives
Sub ClassCorrinoids
Other Descriptors
  • Aromatic Heteropolycyclic Compounds
  • Organic Compounds
  • Benzimidazole
  • Carboxamide Group
  • Diterpene
  • Enamine
  • Imidazole
  • Imine
  • Lactam
  • Metallotetrapyrrole Skeleton
  • Nitrile
  • Organic Hypophosphite
  • Organic Phosphite
  • Organic Transition Metal Moeity
  • Organometallic Compound
  • Oxolane
  • Phosphoric Acid Ester
  • Primary Alcohol
  • Primary Carboxylic Acid Amide
  • Pyrrolidine
  • Pyrroline
  • Quaternary Ammonium Salt
  • Secondary Alcohol
  • Secondary Carboxylic Acid Amide
  • Toluene
Direct ParentCobalamin Derivatives
StatusDetected and Quantified
  • Drug
  • Food
  • Antianemic Agents
  • Essential vitamins
  • Vitamins (Vitamin B Complex)
  • Pharmaceutical
Cellular locations
  • Membrane (predicted from logP)
Physical Properties
Experimental Properties
Melting Point> 300 °CNot Available
Boiling PointNot AvailableNot Available
Water Solubility12.5 mg/mLNot Available
LogPNot AvailableNot Available
Predicted Properties
Water Solubility0.2ALOGPS
Physiological Charge0ChemAxon
Hydrogen Acceptor Count0ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area500.2 Å2ChemAxon
Rotatable Bond Count16ChemAxon
Refractivity356.23 m3·mol-1ChemAxon
Polarizability136.78 Å3ChemAxon
SpectraNot Available
Biological Properties
Cellular Locations
  • Membrane (predicted from logP)
Biofluid Locations
  • Blood
  • Cerebrospinal Fluid (CSF)
  • Urine
Tissue Location
  • Adrenal Cortex
  • Adrenal Gland
  • Adrenal Medulla
  • All Tissues
  • Bladder
  • Brain
  • Epidermis
  • Fibroblasts
  • Gonads
  • Intestine
  • Kidney
  • Liver
  • Muscle
  • Nerve Cells
  • Neuron
  • Pancreas
  • Placenta
  • Platelet
  • Prostate
  • Testes
  • Thyroid Gland
PathwaysNot Available
Normal Concentrations
BloodDetected and Quantified0.00037 (0.00009-0.00155) uMNewborn (0-30 days old)BothNormal
    • Geigy Scientific ...
BloodDetected and Quantified0.00025 +/- 0.00008 uMAdult (>18 years old)BothNormal details
BloodDetected and Quantified0.0002385 +/- 0.0000991 uMAdult (>18 years old)BothNormal details
BloodDetected and Quantified0.00013 (0.00004-0.00050) uMChildren (1-13 years old)BothNormal
    • Geigy Scientific ...
BloodDetected and Quantified0.00028 +/- 0.00012 uMAdult (>18 years old)FemaleNormal
    • Geigy Scientific ...
BloodDetected and Quantified0.0003 +/- 0.0001 uMAdult (>18 years old)MaleNormal
    • Geigy Scientific ...
Cerebrospinal Fluid (CSF)Detected and Quantified0.000016 +/- 0.0000057 uMAdult (>18 years old)BothNormal
    • Geigy Scientific ...
UrineDetected and Quantified0.000006 +/- 0.000002 umol/mmol creatinineAdult (>18 years old)BothNormal details
Abnormal Concentrations
BloodDetected and Quantified0.00055 +/- 0.00041 uMAdult (>18 years old)BothHomozygous sickle cell disease details
Associated Disorders and Diseases
Disease References
Homozygous sickle cell disease
  1. van der Dijs FP, Schnog JJ, Brouwer DA, Velvis HJ, van den Berg GA, Bakker AJ, Duits AJ, Muskiet FD, Muskiet FA: Elevated homocysteine levels indicate suboptimal folate status in pediatric sickle cell patients. Am J Hematol. 1998 Nov;59(3):192-8. Pubmed: 9798656
Associated OMIM IDsNone
DrugBank IDDB00115
DrugBank Metabolite IDNot Available
Phenol Explorer Compound IDNot Available
Phenol Explorer Metabolite IDNot Available
FoodDB IDFDB013264
KNApSAcK IDNot Available
Chemspider IDNot Available
KEGG Compound IDC02823
BioCyc IDCPD-315
BiGG IDNot Available
Wikipedia LinkCyanocobalamin
NuGOwiki LinkHMDB00607
Metagene LinkHMDB00607
PubChem CompoundNot Available
PDB IDNot Available
ChEBI ID17439
Synthesis ReferenceGardner, N.; Champagne, C. P. Production of Propionibacterium shermanii biomass and vitamin B12 on spent media. Journal of Applied Microbiology (2005), 99(5), 1236-1245.
Material Safety Data Sheet (MSDS)Download (PDF)
General References
  1. Cupp MS, Zhang D, Cupp EW: Horn fly (Diptera: Muscidae) saliva targets thrombin action in hemostasis. J Med Entomol. 2000 May;37(3):416-21. Pubmed: 15535586
  2. Waters RS, Bryden NA, Patterson KY, Veillon C, Anderson RA: EDTA chelation effects on urinary losses of cadmium, calcium, chromium, cobalt, copper, lead, magnesium, and zinc. Biol Trace Elem Res. 2001 Dec;83(3):207-21. Pubmed: 11794513
  3. Reznichenko AM, Fesenko VP, Shestopalov DV, Tatarchuk PA: [Changes in cell immunity indexes under the influence of thymalin, thyroxine and fibronectin in patients with hyperplastic diseases of thyroid gland before and after the surgery] Klin Khir. 2001 Dec;(12):31-3. Pubmed: 11944270
  4. Hermann K, Rittweger R, Ring J: Urinary excretion of angiotensin I, II, arginine vasopressin and oxytocin in patients with anaphylactoid reactions. Clin Exp Allergy. 1992 Sep;22(9):845-53. Pubmed: 1422942
  5. Nilsson-Ehle H, Jagenburg R, Landahl S, Lindstedt G, Swolin B, Westin J: Cyanocobalamin absorption in the elderly: results for healthy subjects and for subjects with low serum cobalamin concentration. Clin Chem. 1986 Jul;32(7):1368-71. Pubmed: 3719947
  6. Sesso RM, Iunes Y, Melo AC: Myeloneuropathy following nitrous oxide anesthaesia in a patient with macrocytic anaemia. Neuroradiology. 1999 Aug;41(8):588-90. Pubmed: 10447571
  7. No evidence of association between prothrombotic gene polymorphisms and the development of acute myocardial infarction at a young age. Circulation. 2003 Mar 4;107(8):1117-22. Pubmed: 12615788
  8. Oh Y, Beukers MW, Pham HM, Smanik PA, Smith MC, Rosenfeld RG: Altered affinity of insulin-like growth factor II (IGF-II) for receptors and IGF-binding proteins, resulting from limited modifications of the IGF-II molecule. Biochem J. 1991 Aug 15;278 ( Pt 1):249-54. Pubmed: 1715685
  9. Hoffer LJ, Saboohi F, Golden M, Barre PE: Cobalamin dose regimen for maximum homocysteine reduction in end-stage renal disease. Metabolism. 2005 Jun;54(6):835-40. Pubmed: 15931623
  10. Hohlagschwandtner M, Unfried G, Heinze G, Huber JC, Nagele F, Tempfer C: Combined thrombophilic polymorphisms in women with idiopathic recurrent miscarriage. Fertil Steril. 2003 May;79(5):1141-8. Pubmed: 12738509
  11. Pittock SJ, Payne TA, Harper CM: Reversible myelopathy in a 34-year-old man with vitamin B12 deficiency. Mayo Clin Proc. 2002 Mar;77(3):291-4. Pubmed: 11888035
  12. Houeto P, Buneaux F, Galliot-Guilley M, Baud FJ, Levillain P: Determination of hydroxocobalamin and cyanocobalamin by derivative spectrophotometry in cyanide poisoning. J Anal Toxicol. 1994 May-Jun;18(3):154-8. Pubmed: 8065126
  13. Manier JW, Beltaos E: Benign gastric ulcer in a patient with pernicious anemia. Gastroenterology. 1975 Sep;69(3):744-5. Pubmed: 1158091
  14. Mayer G, Kroger M, Meier-Ewert K: Effects of vitamin B12 on performance and circadian rhythm in normal subjects. Neuropsychopharmacology. 1996 Nov;15(5):456-64. Pubmed: 8914118
  15. Lao JI, Montoriol C, Morer I, Beyer K: Genetic contribution to aging: deleterious and helpful genes define life expectancy. Ann N Y Acad Sci. 2005 Dec;1057:50-63. Pubmed: 16399887
  16. Baumann H, Muller-Eberhard U: Synthesis of hemopexin and cysteine protease inhibitor is coordinately regulated by HSF-II and interferon-beta 2 in rat hepatoma cells. Biochem Biophys Res Commun. 1987 Aug 14;146(3):1218-28. Pubmed: 3304291
  17. Houeto P, Hoffman JR, Imbert M, Levillain P, Baud FJ: Relation of blood cyanide to plasma cyanocobalamin concentration after a fixed dose of hydroxocobalamin in cyanide poisoning. Lancet. 1995 Sep 2;346(8975):605-8. Pubmed: 7651005
  18. van Asselt DZ, van den Broek WJ, Lamers CB, Corstens FH, Hoefnagels WH: Free and protein-bound cobalamin absorption in healthy middle-aged and older subjects. J Am Geriatr Soc. 1996 Aug;44(8):949-53. Pubmed: 8708306
  19. Wu H, Bruley DF: Homologous human blood protein separation using immobilized metal affinity chromatography: protein C separation from prothrombin with application to the separation of factor IX and prothrombin. Biotechnol Prog. 1999 Sep-Oct;15(5):928-31. Pubmed: 10514264
  20. Hall AH, Rumack BH: Hydroxycobalamin/sodium thiosulfate as a cyanide antidote. J Emerg Med. 1987;5(2):115-21. Pubmed: 3295013
  21. Wickramasinghe SN: Morphology, biology and biochemistry of cobalamin- and folate-deficient bone marrow cells. Baillieres Clin Haematol. 1995 Sep;8(3):441-59. Pubmed: 8534956
  22. Gilligan MA: Metformin and vitamin B12 deficiency. Arch Intern Med. 2002 Feb 25;162(4):484-5. Pubmed: 11863489
  23. Andres E, Noel E, Goichot B: Metformin-associated vitamin B12 deficiency. Arch Intern Med. 2002 Oct 28;162(19):2251-2. Pubmed: 12390080
  24. Sharabi A, Cohen E, Sulkes J, Garty M: Replacement therapy for vitamin B12 deficiency: comparison between the sublingual and oral route. Br J Clin Pharmacol. 2003 Dec;56(6):635-8. Pubmed: 14616423


General function:
Involved in cobalamin binding
Specific function:
Catalyzes the transfer of a methyl group from methyl-cobalamin to homocysteine, yielding enzyme-bound cob(I)alamin and methionine. Subsequently, remethylates the cofactor using methyltetrahydrofolate (By similarity).
Gene Name:
Uniprot ID:
Molecular weight:
  1. Stover PJ: Vitamin B12 and older adults. Curr Opin Clin Nutr Metab Care. 2010 Jan;13(1):24-7. Pubmed: 19904199
  2. Allen LH: Causes of vitamin B12 and folate deficiency. Food Nutr Bull. 2008 Jun;29(2 Suppl):S20-34; discussion S35-7. Pubmed: 18709879
General function:
Involved in methylenetetrahydrofolate reductase (NADPH) activity
Specific function:
Catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a co-substrate for homocysteine remethylation to methionine.
Gene Name:
Uniprot ID:
Molecular weight:
  1. Nakamura T, Saionji K, Hiejima Y, Hirayama H, Tago K, Takano H, Tajiri M, Hayashi K, Kawabata M, Funamizu M, Makita Y, Hata A: Methylenetetrahydrofolate reductase genotype, vitamin B12, and folate influence plasma homocysteine in hemodialysis patients. Am J Kidney Dis. 2002 May;39(5):1032-9. Pubmed: 11979347
  2. Erdogan MO, Yildiz SH, Solak M, Eser O, Cosar E, Eser B, Koken R, Buyukbas S: C677T polymorphism of the methylenetetrahydrofolate reductase gene does not affect folic acid, vitamin B12, and homocysteine serum levels in Turkish children with neural tube defects. Genet Mol Res. 2010 Jun 22;9(2):1197-203. Pubmed: 20589617
General function:
Involved in isomerase activity
Specific function:
Involved in the degradation of several amino acids, odd-chain fatty acids and cholesterol via propionyl-CoA to the tricarboxylic acid cycle. MCM has different functions in other species.
Gene Name:
Uniprot ID:
Molecular weight:
  1. Worgan LC, Niles K, Tirone JC, Hofmann A, Verner A, Sammak A, Kucic T, Lepage P, Rosenblatt DS: Spectrum of mutations in mut methylmalonic acidemia and identification of a common Hispanic mutation and haplotype. Hum Mutat. 2006 Jan;27(1):31-43. Pubmed: 16281286
  2. Brooks AJ, Vlasie M, Banerjee R, Brunold TC: Co-C bond activation in methylmalonyl-CoA mutase by stabilization of the post-homolysis product Co2+ cobalamin. J Am Chem Soc. 2005 Nov 30;127(47):16522-8. Pubmed: 16305240
  3. Kozlowski PM, Andruniow T, Jarzecki AA, Zgierski MZ, Spiro TG: DFT analysis of co-alkyl and co-adenosyl vibrational modes in B12-cofactors. Inorg Chem. 2006 Jul 10;45(14):5585-90. Pubmed: 16813422
  4. Moras E, Hosack A, Watkins D, Rosenblatt DS: Mitochondrial vitamin B12-binding proteins in patients with inborn errors of cobalamin metabolism. Mol Genet Metab. 2007 Feb;90(2):140-7. Epub 2006 Sep 29. Pubmed: 17011224
  5. Stover PJ: Vitamin B12 and older adults. Curr Opin Clin Nutr Metab Care. 2010 Jan;13(1):24-7. Pubmed: 19904199
General function:
Involved in oxidoreductase activity
Specific function:
Involved in the reductive regeneration of cob(I)alamin cofactor required for the maintenance of methionine synthase in a functional state.
Gene Name:
Uniprot ID:
Molecular weight:
  1. O'Leary VB, Mills JL, Pangilinan F, Kirke PN, Cox C, Conley M, Weiler A, Peng K, Shane B, Scott JM, Parle-McDermott A, Molloy AM, Brody LC: Analysis of methionine synthase reductase polymorphisms for neural tube defects risk association. Mol Genet Metab. 2005 Jul;85(3):220-7. Epub 2005 Mar 17. Pubmed: 15979034
  2. Gueant-Rodriguez RM, Juilliere Y, Candito M, Adjalla CE, Gibelin P, Herbeth B, Van Obberghen E, Gueant JL: Association of MTRRA66G polymorphism (but not of MTHFR C677T and A1298C, MTRA2756G, TCN C776G) with homocysteine and coronary artery disease in the French population. Thromb Haemost. 2005 Sep;94(3):510-5. Pubmed: 16268464
  3. Miriuka SG, Langman LJ, Evrovski J, Miner SE, D'Mello N, Delgado DH, Wong BY, Ross HJ, Cole DE: Genetic polymorphisms predisposing to hyperhomocysteinemia in cardiac transplant patients. Transpl Int. 2005 Jan;18(1):29-35. Pubmed: 15612980
  4. Berkun Y, Abou Atta I, Rubinow A, Orbach H, Levartovsky D, Aamar S, Arbel O, Dresner-Pollak R, Friedman G, Ben-Yehuda A: 2756GG genotype of methionine synthase reductase gene is more prevalent in rheumatoid arthritis patients treated with methotrexate and is associated with methotrexate-induced nodulosis. J Rheumatol. 2007 Aug;34(8):1664-9. Epub 2007 Jul 1. Pubmed: 17611986
  5. van der Linden IJ, den Heijer M, Afman LA, Gellekink H, Vermeulen SH, Kluijtmans LA, Blom HJ: The methionine synthase reductase 66A>G polymorphism is a maternal risk factor for spina bifida. J Mol Med (Berl). 2006 Dec;84(12):1047-54. Epub 2006 Oct 6. Pubmed: 17024475
General function:
Involved in ATP binding
Specific function:
Not Available
Gene Name:
Uniprot ID:
Molecular weight:
  1. Zhang J, Dobson CM, Wu X, Lerner-Ellis J, Rosenblatt DS, Gravel RA: Impact of cblB mutations on the function of ATP:cob(I)alamin adenosyltransferase in disorders of vitamin B12 metabolism. Mol Genet Metab. 2006 Apr;87(4):315-22. Epub 2006 Jan 24. Pubmed: 16439175
  2. Lerner-Ellis JP, Gradinger AB, Watkins D, Tirone JC, Villeneuve A, Dobson CM, Montpetit A, Lepage P, Gravel RA, Rosenblatt DS: Mutation and biochemical analysis of patients belonging to the cblB complementation class of vitamin B12-dependent methylmalonic aciduria. Mol Genet Metab. 2006 Mar;87(3):219-25. Epub 2006 Jan 10. Pubmed: 16410054
General function:
Involved in nucleotide binding
Specific function:
Probable GTPase. May function as chaperone. May be involved in the transport of cobalamin (Cbl) into mitochondria for the final steps of adenosylcobalamin (AdoCbl) synthesis
Gene Name:
Uniprot ID:
Molecular weight:
  1. Overington JP, Al-Lazikani B, Hopkins AL: How many drug targets are there? Nat Rev Drug Discov. 2006 Dec;5(12):993-6. Pubmed: 17139284
  2. Imming P, Sinning C, Meyer A: Drugs, their targets and the nature and number of drug targets. Nat Rev Drug Discov. 2006 Oct;5(10):821-34. Pubmed: 17016423
  3. Lerner-Ellis JP, Dobson CM, Wai T, Watkins D, Tirone JC, Leclerc D, Dore C, Lepage P, Gravel RA, Rosenblatt DS: Mutations in the MMAA gene in patients with the cblA disorder of vitamin B12 metabolism. Hum Mutat. 2004 Dec;24(6):509-16. Pubmed: 15523652
  4. Dobson CM, Gradinger A, Longo N, Wu X, Leclerc D, Lerner-Ellis J, Lemieux M, Belair C, Watkins D, Rosenblatt DS, Gravel RA: Homozygous nonsense mutation in the MCEE gene and siRNA suppression of methylmalonyl-CoA epimerase expression: a novel cause of mild methylmalonic aciduria. Mol Genet Metab. 2006 Aug;88(4):327-33. Epub 2006 May 11. Pubmed: 16697227
General function:
Involved in cobalamin binding
Specific function:
May be involved in the binding and intracellular trafficking of cobalamin (vitamin B12)
Gene Name:
Uniprot ID:
Molecular weight:
  1. Chandler RJ, Aswani V, Tsai MS, Falk M, Wehrli N, Stabler S, Allen R, Sedensky M, Kazazian HH, Venditti CP: Propionyl-CoA and adenosylcobalamin metabolism in Caenorhabditis elegans: evidence for a role of methylmalonyl-CoA epimerase in intermediary metabolism. Mol Genet Metab. 2006 Sep-Oct;89(1-2):64-73. Epub 2006 Jul 14. Pubmed: 16843692
  2. Ben-Omran TI, Wong H, Blaser S, Feigenbaum A: Late-onset cobalamin-C disorder: a challenging diagnosis. Am J Med Genet A. 2007 May 1;143A(9):979-84. Pubmed: 17431913
  3. Morel CF, Lerner-Ellis JP, Rosenblatt DS: Combined methylmalonic aciduria and homocystinuria (cblC): phenotype-genotype correlations and ethnic-specific observations. Mol Genet Metab. 2006 Aug;88(4):315-21. Epub 2006 May 22. Pubmed: 16714133
  4. Lerner-Ellis JP, Tirone JC, Pawelek PD, Dore C, Atkinson JL, Watkins D, Morel CF, Fujiwara TM, Moras E, Hosack AR, Dunbar GV, Antonicka H, Forgetta V, Dobson CM, Leclerc D, Gravel RA, Shoubridge EA, Coulton JW, Lepage P, Rommens JM, Morgan K, Rosenblatt DS: Identification of the gene responsible for methylmalonic aciduria and homocystinuria, cblC type. Nat Genet. 2006 Jan;38(1):93-100. Epub 2005 Nov 27. Pubmed: 16311595


General function:
Involved in cobalamin binding
Specific function:
Primary vitamin B12-binding and transport protein. Delivers cobalamin to cells
Gene Name:
Uniprot ID:
Molecular weight:
  1. Chen X, Remacha AF, Sarda MP, Carmel R: Influence of cobalamin deficiency compared with that of cobalamin absorption on serum holo-transcobalamin II. Am J Clin Nutr. 2005 Jan;81(1):110-4. Pubmed: 15640468
  2. Alessio AC, Hoehr NF, Siqueira LH, Bydlowski SP, Annichino-Bizzacchi JM: Polymorphism C776G in the transcobalamin II gene and homocysteine, folate and vitamin B12 concentrations. Association with MTHFR C677T and A1298C and MTRR A66G polymorphisms in healthy children. Thromb Res. 2007;119(5):571-7. Epub 2006 Jul 3. Pubmed: 16820193
  3. Bowen RA, Drake SK, Vanjani R, Huey ED, Grafman J, Horne MK 3rd: Markedly increased vitamin B12 concentrations attributable to IgG-IgM-vitamin B12 immune complexes. Clin Chem. 2006 Nov;52(11):2107-14. Pubmed: 17068171
  4. Bosco P, Gueant-Rodriguez RM, Anello G, Spada R, Romano A, Fajardo A, Caraci F, Ferri R, Gueant JL: Association of homocysteine (but not of MTHFR 677 C>T, MTR 2756 A>G, MTRR 66 A>G and TCN2 776 C>G) with ischaemic cerebrovascular disease in Sicily. Thromb Haemost. 2006 Aug;96(2):154-9. Pubmed: 16894458
  5. Al-Alami JR, Tanner SM, Tayeh MK, de la Chapelle A, El-Shanti H: Homozygous AMN mutation in hereditary selective intestinal malabsorption of vitamin B12 in Jordan. Saudi Med J. 2005 Jul;26(7):1061-4. Pubmed: 16047053
General function:
Involved in cobalamin binding
Specific function:
Vitamin B12-binding protein. Transports cobalamin into cells
Gene Name:
Uniprot ID:
Molecular weight:
  1. Carmel R: Haptocorrin (transcobalamin I) and cobalamin deficiencies. Clin Chem. 2007 Feb;53(2):367-8; author reply 368-9. Pubmed: 17259255
  2. Al-Alami JR, Tanner SM, Tayeh MK, de la Chapelle A, El-Shanti H: Homozygous AMN mutation in hereditary selective intestinal malabsorption of vitamin B12 in Jordan. Saudi Med J. 2005 Jul;26(7):1061-4. Pubmed: 16047053
General function:
Involved in cobalamin binding
Specific function:
Promotes absorption of the essential vitamin cobalamin (Cbl) in the ileum by specific receptor-mediated endocytosis
Gene Name:
Uniprot ID:
Molecular weight:
  1. Fedosov SN, Fedosova NU, Berglund L, Moestrup SK, Nexo E, Petersen TE: Composite organization of the cobalamin binding and cubilin recognition sites of intrinsic factor. Biochemistry. 2005 Mar 8;44(9):3604-14. Pubmed: 15736970
  2. He Q, Madsen M, Kilkenney A, Gregory B, Christensen EI, Vorum H, Hojrup P, Schaffer AA, Kirkness EF, Tanner SM, de la Chapelle A, Giger U, Moestrup SK, Fyfe JC: Amnionless function is required for cubilin brush-border expression and intrinsic factor-cobalamin (vitamin B12) absorption in vivo. Blood. 2005 Aug 15;106(4):1447-53. Epub 2005 Apr 21. Pubmed: 15845892
  3. Moestrup SK: New insights into carrier binding and epithelial uptake of the erythropoietic nutrients cobalamin and folate. Curr Opin Hematol. 2006 May;13(3):119-23. Pubmed: 16567952
General function:
Involved in calcium ion binding
Specific function:
Cotransporter which plays a role in lipoprotein, vitamin and iron metabolism, by facilitating their uptake. Binds to ALB, MB, Kappa and lambda-light chains, TF, hemoglobin, GC, SCGB1A1, APOA1, high density lipoprotein, and the GIF-cobalamin complex. The binding of all ligands required calcium. Serves as important transporter in several absorptive epithelia, including intestine, renal proximal tubules and embryonic yolk sac. Interaction with LRP2 mediates its trafficking throughout vesicles and facilitates the uptake of specific ligands like GC, hemoglobin, ALB, TF and SCGB1A1. Interaction with AMN controls its trafficking to the plasma membrane and facilitates endocytosis of ligands. May play an important role in the development of the peri-implantation embryo through internalization of APOA1 and cholesterol. Binds to LGALS3 at the maternal-fetal interface
Gene Name:
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  1. Fedosov SN, Fedosova NU, Berglund L, Moestrup SK, Nexo E, Petersen TE: Composite organization of the cobalamin binding and cubilin recognition sites of intrinsic factor. Biochemistry. 2005 Mar 8;44(9):3604-14. Pubmed: 15736970
  2. He Q, Madsen M, Kilkenney A, Gregory B, Christensen EI, Vorum H, Hojrup P, Schaffer AA, Kirkness EF, Tanner SM, de la Chapelle A, Giger U, Moestrup SK, Fyfe JC: Amnionless function is required for cubilin brush-border expression and intrinsic factor-cobalamin (vitamin B12) absorption in vivo. Blood. 2005 Aug 15;106(4):1447-53. Epub 2005 Apr 21. Pubmed: 15845892
  3. Moestrup SK: New insights into carrier binding and epithelial uptake of the erythropoietic nutrients cobalamin and folate. Curr Opin Hematol. 2006 May;13(3):119-23. Pubmed: 16567952
General function:
Involved in multicellular organismal development
Specific function:
Necessary for efficient absorption of vitamin B12. May direct the production of trunk mesoderm during development by modulating a bone morphogenetic protein (BMP) signaling pathway in the underlying visceral endoderm
Gene Name:
Uniprot ID:
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  1. Al-Alami JR, Tanner SM, Tayeh MK, de la Chapelle A, El-Shanti H: Homozygous AMN mutation in hereditary selective intestinal malabsorption of vitamin B12 in Jordan. Saudi Med J. 2005 Jul;26(7):1061-4. Pubmed: 16047053