Cyanocobalamin 50microgram tablets
Pharmacy only
Available from a pharmacy with pharmacist advice
Tablet
Oral
Cyanocobalamin (commonly known as Vitamin B12) is a highly complex, essential vitamin, owing its name to the fact that it contains the mineral, cobalt.
Active ingredients:
Cyanocobalamin
1 safety notice
Safety information for pregnancy and breastfeeding
Category C
Risk cannot be ruled outPregnancy
Use in pregnancy
No adverse effects have been reported with ingestion of normal daily requirements during pregnancy F3736.
No adverse effects have been reported with ingestion of normal daily requirements during pregnancy F3736.
A note on the use of the nasal spray in pregnancy
Although vitamin B12 is an essential vitamin and requirements are increased during pregnancy, it is currently unknown whether the nasal spray form can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity.
Although vitamin B12 is an essential vitamin and requirements are increased during pregnancy, it is currently unknown whether the nasal spray form can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity.
The nasal spray form should be given to a pregnant woman only if clearly needed, as it is considered a pregnancy category C drug in this form.
Sufficient well-controlled studies have not been done to this date in pregnant women [FDA label].
Use in lactation
Vitamin B12 has been found distributed into the milk of nursing women in concentrations similar to the maternal blood vitamin B12 concentrations.
Vitamin B12 has been found distributed into the milk of nursing women in concentrations similar to the maternal blood vitamin B12 concentrations.
Breastfeeding
Use in lactation
Vitamin B12 has been found distributed into the milk of nursing women in concentrations similar to the maternal blood vitamin B12 concentrations.
Vitamin B12 has been found distributed into the milk of nursing women in concentrations similar to the maternal blood vitamin B12 concentrations.
No adverse effects have been reported to date with intake of normal required doses during lactation F3736.
Always consult your doctor or midwife before taking any medicine during pregnancy or while breastfeeding. Source: DrugBank (CC BY-NC 4.0).
Official documents, adverse reaction reporting, and safety monitoring
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Source: MHRA Products DatabaseOGL 3.0
Updated 3 months ago(16 Jan 2026)Safety monitoring data
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Suspected adverse reactions reported for Cyanocobalamin
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Cyanocobalamin 50microgram tablets
Cyanocobalamin 50microgram tablets
Cyanocobalamin 50microgram tablets
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£1.77indicative price
This is the NHS Drug Tariff indicative price used for reimbursement purposes. It may not reflect the price paid by patients or pharmacies.
View full Drug TariffSource: NHS Drug Tariff via NHSBSA. Derived from dm+d VMPP (Virtual Medicinal Product Pack) pricing data. Contains public sector information licensed under the Open Government Licence v3.0.
WHO defined daily dose (DDD)
1 mg
Not a recommended dose. The DDD is the assumed average maintenance dose per day for a drug used for its main indication in adults. It is a statistical measure used for research and comparison purposes only.
Source: WHO Collaborating Centre for Drug Statistics Methodology, distributed via NHS dm+d BNF mapping files. Contains public sector information licensed under the Open Government Licence v3.0.
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Similarity based on WHO Anatomical Therapeutic Chemical (ATC) classification and NHS BNF section grouping. Source data: NHS dm+d via TRUD (OGL v3.0), WHO ATC/DDD Index.
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Clinical guidelines and formulary information
British National Formulary
Cyanocobalamin
BNF
Drug monograph — bnf.nice.org.ukSource: British National Formulary, NICE. Joint Formulary Committee. Contains public sector information licensed under the Open Government Licence v3.0.
NICE clinical guidance(1)
Source: National Institute for Health and Care Excellence (NICE). Contains public sector information licensed under the Open Government Licence v3.0.
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Codes for healthcare professionals and prescribing systems
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SNOMED CT and dm+d codes from NHS TRUD (Technology Reference data Update Distribution), licensed under the Open Government Licence v3.0. BNF codes from NHS Business Services Authority (NHSBSA). ATC codes from the WHO Collaborating Centre for Drug Statistics Methodology (whocc.no).
Active and completed clinical studies from ClinicalTrials.gov
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Searching UK clinical trials...
Source: ClinicalTrials.gov, a database of the U.S. National Library of Medicine (NLM), National Institutes of Health (NIH). Data accessed via ClinicalTrials.gov API v2. Trial information is provided for research purposes and does not constitute medical advice.
Pharmacology and chemical data from DrugBank
Key facts
Drug status
Approved
Major interactions
None known
Half-life
6 days
Mechanism
Vitamin B12 serves as a cofactor for methionine synthase and L-methylmalonyl-CoA mutase enzymes.
Food interactions
1 warning
Human targets
6 targets
Data: DrugBank · CC BY-NC 4.0
Pharmacokinetics at a glance
Absorption
1 hour
Vitamin B12 is quickly absorbed from intramuscular (IM) and subcutaneous (SC) sites of injection; with peak plasma concentrations achieved about 1 hour after IM injection F3736.
Orally…
Orally…
Half-life
6 days
Approximately 6 days (400 days in the liver) F3739.
Protein binding
Very high (to specific plasma proteins called transcobalamins); binding of hydroxocobalamin is slightly higher than cyanocobalamin [FDA label.
Volume of distribution
Cobalamin is distributed to tissues and stored mainly in the liver and bone marrow [FDA label].
Metabolism
Vitamin B12 or cyanocobalamin obtained from food is initially bound by haptocorrin, a protein found in the saliva with high affinity for B12.…
Elimination
This drug is partially excreted in the urine F3739. According to a clinical study, approximately 3-8 mcg of vitamin B12 is secreted into the gastrointestinal tract daily via the bile.…
Clearance
During vitamin loading, the kidney accumulates large amounts of unbound vitamin B12.…
Pharmacokinetic data: DrugBank · CC BY-NC 4.0
Status:
Approved
Investigational
Nutraceutical
Small molecule
About this compound
Cyanocobalamin (commonly known as Vitamin B12) is a highly complex, essential vitamin, owing its name to the fact that it contains the mineral, cobalt. This vitamin is produced naturally by bacteria [A175276], and is necessary for DNA synthesis and cellular energy production. Vitamin B12 has many forms, including the cyano-, methyl-, deoxyadenosyl- and hydroxy-cobalamin forms. The cyano form, is the most widely used form in supplements and prescription drugs [A175255], [FDA label]. Several pharmaceutical forms of cyanocobalamin have been developed, including the tablet, injection, and nasal spray forms [FDA label], [L5542], [L5545]. This drug was initially approved by the FDA in 1942 [FDA label].
Properties:
View FDA drug labelsolid
Avg. mass: 1355.37 Da
DrugBank indication
Nasal spray
The cyanocobalamin nasal spray is indicated for the maintenance of vitamin B12 concentrations after normalization with intramuscular vitamin B12 therapy in patients with deficiency of this vitamin who have no nervous system involvement [FDA label].
Note: CaloMist [FDA label], the nasal spray form, has not been evaluated for the treatment of newly diagnosed vitamin B12 deficiency.
Injection forms (subcutaneous, intramuscular)
These forms are indicated for vitamin B12 deficiencies due to various causes, with or without neurologic manifestations F3736. Vitamin B12 deficiency is frequently caused by malabsorption, which is often associated with the following conditions [L5545]:
Addisonian (pernicious) anemia
Gastrointestinal pathology, dysfunction, or surgery, including gluten enteropathy or sprue, small bowel bacterial overgrowth, total or partial gastrectomy
Fish tapeworm infestation
Malignancy of the pancreas or bowel
Folic acid deficiency
Oral forms
Vitamin B12 supplements are widely available and indicated in patients who require supplementation for various reasons. Dose requirements for vitamin B12 which are higher than normal (caused by pregnancy, thyrotoxicosis, hemolytic anemia, hemorrhage, malignancy, hepatic and renal disease) can usually be achieved with oral supplementation .
[L5545]
Oral products of vitamin B12 are not recommended in patients with malabsorption, as these forms are primarily absorbed in the gastrointestinal tract F3739.
The cyanocobalamin nasal spray is indicated for the maintenance of vitamin B12 concentrations after normalization with intramuscular vitamin B12 therapy in patients with deficiency of this vitamin who have no nervous system involvement [FDA label].
Note: CaloMist [FDA label], the nasal spray form, has not been evaluated for the treatment of newly diagnosed vitamin B12 deficiency.
Injection forms (subcutaneous, intramuscular)
These forms are indicated for vitamin B12 deficiencies due to various causes, with or without neurologic manifestations F3736. Vitamin B12 deficiency is frequently caused by malabsorption, which is often associated with the following conditions [L5545]:
Addisonian (pernicious) anemia
Gastrointestinal pathology, dysfunction, or surgery, including gluten enteropathy or sprue, small bowel bacterial overgrowth, total or partial gastrectomy
Fish tapeworm infestation
Malignancy of the pancreas or bowel
Folic acid deficiency
Oral forms
Vitamin B12 supplements are widely available and indicated in patients who require supplementation for various reasons. Dose requirements for vitamin B12 which are higher than normal (caused by pregnancy, thyrotoxicosis, hemolytic anemia, hemorrhage, malignancy, hepatic and renal disease) can usually be achieved with oral supplementation .
[L5545]
Oral products of vitamin B12 are not recommended in patients with malabsorption, as these forms are primarily absorbed in the gastrointestinal tract F3739.
Also known as(66)
Cianocobalamina
Cyanocob(III)alamin
Cyanocobalamin
Cyanocobalamine
Cyanocobalaminum
Vitamin B12 NOS
2.1.1.13
5-methyltetrahydrofolate--homocysteine methyltransferase
Dosage forms(203)
Powder, for solution (Intramuscular)
Capsule; liquid (Oral)
Tablet, coated (Oral) — 1 mg
Liquid (Intraocular)
Solution (Intramuscular)
Solution (Intravenous) — 1.914 mg
Tablet (Oral) — 1000 ug/1
Tablet (Oral) — 500 ug/1
Molecular properties(19)
Drug interactions(789)
Known interactions with other medications. Always consult a healthcare professional.
Chloramphenicol
Moderate
The therapeutic efficacy of Cyanocobalamin can be decreased when used in combination with Chloramphenicol.
Colchicine
Moderate
The therapeutic efficacy of Cyanocobalamin can be decreased when used in combination with Colchicine.
Cyclosporine
Moderate
Cyclosporine may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Cefotiam may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Mesalazine
Moderate
Mesalazine may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Cefmenoxime
Moderate
Cefmenoxime may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Cefmetazole
Moderate
Cefmetazole may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Pamidronic acid
Moderate
Pamidronic acid may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Tenofovir disoproxil
Moderate
Tenofovir disoproxil may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Cidofovir may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Cefpiramide
Moderate
Cefpiramide may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Ceftazidime
Moderate
Ceftazidime may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Loracarbef
Moderate
Loracarbef may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Cefalotin may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Nabumetone
Moderate
Nabumetone may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Tenoxicam may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Celecoxib may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Cefotaxime
Moderate
Cefotaxime may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Tolmetin may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Foscarnet may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Rofecoxib may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Piroxicam may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Cephalexin
Moderate
Cephalexin may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Fenoprofen
Moderate
Fenoprofen may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Valaciclovir
Moderate
Valaciclovir may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Valdecoxib
Moderate
Valdecoxib may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Sulindac may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Bacitracin
Moderate
Bacitracin may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Amphotericin B
Moderate
Amphotericin B may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Cephaloglycin
Moderate
Cephaloglycin may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Flurbiprofen
Moderate
Flurbiprofen may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Adefovir dipivoxil
Moderate
Adefovir dipivoxil may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Pentamidine
Moderate
Pentamidine may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Etodolac may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Mefenamic acid
Moderate
Mefenamic acid may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Acyclovir may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Naproxen may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Sulfasalazine
Moderate
Sulfasalazine may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Phenylbutazone
Moderate
Phenylbutazone may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Carprofen may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Cefaclor may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Diflunisal
Moderate
Diflunisal may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Ceforanide
Moderate
Ceforanide may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Salicylic acid
Moderate
Salicylic acid may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Meclofenamic acid
Moderate
Meclofenamic acid may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Acetylsalicylic acid
Moderate
Acetylsalicylic acid may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Oxaprozin may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Balsalazide
Moderate
Balsalazide may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Cefditoren
Moderate
Cefditoren may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Atazanavir
Moderate
Atazanavir may decrease the excretion rate of Cyanocobalamin which could result in a higher serum level.
Showing 50 of 789 interactions
Food & lifestyle interactions
Advice
Take with or without food. Recommendations vary from product to product - consult individual product monographs for additional information.
Toxicity & overdose
LD50 Oral (mouse): > 5,000 mg/kg F3733.
General toxicity
Vitamin B12 is generally non-toxic, even at higher doses. Mild, transient diarrhea, polycythemia vera, peripheral vascular thrombosis, itching, transitory exanthema, a feeling of swelling of entire body, pulmonary edema and congestive heart failure in early treatment stages, anaphylactic shock and death have been observed after vitamin B12 administration F3736.
Carcinogenesis and mutagenesis
Long term studies in animals examining the carcinogenic potential of any of the vitamin B12 formulations have not completed to date. There is no evidence from long-term use in patients with pernicious anemia that vitamin B12 has carcinogenic potential. Pernicious
anemia is known to be associated with an increased incidence of stomach carcinoma, however, this malignancy has been attributed to the underlying cause of pernicious anemia and has not been found to be related to treatment with vitamin B12 [FDA label].
Use in pregnancy
No adverse effects have been reported with ingestion of normal daily requirements during pregnancy F3736.
A note on the use of the nasal spray in pregnancy
Although vitamin B12 is an essential vitamin and requirements are increased during pregnancy, it is currently unknown whether the nasal spray form can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity.
The nasal spray form should be given to a pregnant woman only if clearly needed, as it is considered a pregnancy category C drug in this form. Sufficient well-controlled studies have not been done to this date in pregnant women [FDA label].
Use in lactation
Vitamin B12 has been found distributed into the milk of nursing women in concentrations similar to the maternal blood vitamin B12 concentrations. No adverse effects have been reported to date with intake of normal required doses during lactation F3736.
General toxicity
Vitamin B12 is generally non-toxic, even at higher doses. Mild, transient diarrhea, polycythemia vera, peripheral vascular thrombosis, itching, transitory exanthema, a feeling of swelling of entire body, pulmonary edema and congestive heart failure in early treatment stages, anaphylactic shock and death have been observed after vitamin B12 administration F3736.
Carcinogenesis and mutagenesis
Long term studies in animals examining the carcinogenic potential of any of the vitamin B12 formulations have not completed to date. There is no evidence from long-term use in patients with pernicious anemia that vitamin B12 has carcinogenic potential. Pernicious
anemia is known to be associated with an increased incidence of stomach carcinoma, however, this malignancy has been attributed to the underlying cause of pernicious anemia and has not been found to be related to treatment with vitamin B12 [FDA label].
Use in pregnancy
No adverse effects have been reported with ingestion of normal daily requirements during pregnancy F3736.
A note on the use of the nasal spray in pregnancy
Although vitamin B12 is an essential vitamin and requirements are increased during pregnancy, it is currently unknown whether the nasal spray form can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity.
The nasal spray form should be given to a pregnant woman only if clearly needed, as it is considered a pregnancy category C drug in this form. Sufficient well-controlled studies have not been done to this date in pregnant women [FDA label].
Use in lactation
Vitamin B12 has been found distributed into the milk of nursing women in concentrations similar to the maternal blood vitamin B12 concentrations. No adverse effects have been reported to date with intake of normal required doses during lactation F3736.
How it works
Mechanism of action
Vitamin B12 serves as a cofactor for methionine synthase and L-methylmalonyl-CoA mutase enzymes. Methionine synthase is essential for the synthesis of purines and pyrimidines that form DNA. L-methylmalonyl-CoA mutase converts L-methylmalonyl-CoA to succinyl-CoA in the degradation of propionate [L2064], an important reaction required for both fat and protein metabolism. It is a lack of vitamin B12 cofactor in the above reaction and the resulting accumulation of methylmalonyl CoA that is believed to be responsible for the neurological manifestations of B12 deficiency [A175255]. Succinyl-CoA is also necessary for the synthesis of hemoglobin [L2064].
In tissues, vitamin B12 is required for the synthesis of methionine from homocysteine. Methionine is required for the formation of S-adenosylmethionine, a methyl donor for nearly 100 substrates, comprised of DNA, RNA, hormones, proteins, as well as lipids [L2064]. Without vitamin B12, tetrahydrofolate cannot be regenerated from 5-methyltetrahydrofolate, and this can lead to functional folate deficiency [L5554], [FDA label].
This reaction is dependent on methylcobalamin (vitamin B12) as a co-factor and is also dependent on folate, in which the methyl group of methyltetrahydrofolate is transferred to homocysteine to form methionine and tetrahydrofolate. Vitamin B12 incorporates into circulating folic acid into growing red blood cells; retaining the folate in these cells [L5557]. A deficiency of vitamin B12 and the interruption of this reaction leads to the development of megaloblastic anemia.
In tissues, vitamin B12 is required for the synthesis of methionine from homocysteine. Methionine is required for the formation of S-adenosylmethionine, a methyl donor for nearly 100 substrates, comprised of DNA, RNA, hormones, proteins, as well as lipids [L2064]. Without vitamin B12, tetrahydrofolate cannot be regenerated from 5-methyltetrahydrofolate, and this can lead to functional folate deficiency [L5554], [FDA label].
This reaction is dependent on methylcobalamin (vitamin B12) as a co-factor and is also dependent on folate, in which the methyl group of methyltetrahydrofolate is transferred to homocysteine to form methionine and tetrahydrofolate. Vitamin B12 incorporates into circulating folic acid into growing red blood cells; retaining the folate in these cells [L5557]. A deficiency of vitamin B12 and the interruption of this reaction leads to the development of megaloblastic anemia.
Pharmacodynamics
General effects
Cyanocobalamin corrects vitamin B12 deficiency and improves the symptoms and laboratory abnormalities associated with pernicious anemia (megaloblastic indices, gastrointestinal lesions, and neurologic damage). This drug aids in growth, cell reproduction, hematopoiesis, nucleoprotein, and myelin synthesis. It also plays an important role in fat metabolism, carbohydrate metabolism, as well as protein synthesis. Cells that undergo rapid division (for example, epithelial cells, bone marrow, and myeloid cells) have a high demand for vitamin B12 [A175255].
Parenteral cyanocobalamin effects
The parenteral administration of vitamin B12 rapidly and completely reverses the megaloblastic anemia and gastrointestinal symptoms of vitamin B12 deficiency. Rapid parenteral administration of vitamin B12 in deficiency related neurological damage prevents the progression of this condition [L5545].
Nasal spray effects
In 24 vitamin B12 deficient patients who were already stabilized on intramuscular (IM) vitamin B12 therapy, single daily doses of intranasal cyanocobalamin for 8 weeks lead to serum vitamin B12 concentrations that were within the target therapeutic range (>200 ng/L) [FDA label].
Cyanocobalamin corrects vitamin B12 deficiency and improves the symptoms and laboratory abnormalities associated with pernicious anemia (megaloblastic indices, gastrointestinal lesions, and neurologic damage). This drug aids in growth, cell reproduction, hematopoiesis, nucleoprotein, and myelin synthesis. It also plays an important role in fat metabolism, carbohydrate metabolism, as well as protein synthesis. Cells that undergo rapid division (for example, epithelial cells, bone marrow, and myeloid cells) have a high demand for vitamin B12 [A175255].
Parenteral cyanocobalamin effects
The parenteral administration of vitamin B12 rapidly and completely reverses the megaloblastic anemia and gastrointestinal symptoms of vitamin B12 deficiency. Rapid parenteral administration of vitamin B12 in deficiency related neurological damage prevents the progression of this condition [L5545].
Nasal spray effects
In 24 vitamin B12 deficient patients who were already stabilized on intramuscular (IM) vitamin B12 therapy, single daily doses of intranasal cyanocobalamin for 8 weeks lead to serum vitamin B12 concentrations that were within the target therapeutic range (>200 ng/L) [FDA label].
Pharmacokinetics
How the body processes this drug — absorption, distribution, metabolism, and elimination
Absorption
Vitamin B12 is quickly absorbed from intramuscular (IM) and subcutaneous (SC) sites of injection; with peak plasma concentrations achieved about 1 hour after IM injection F3736.
Orally administered vitamin B12 binds to intrinsic factor (IF) during its transport through the stomach. The separation of Vitamin B12 and IF occurs in the terminal ileum when calcium is present, and vitamin B12 is then absorbed into the gastrointestinal mucosal cells. It is then transported by transcobalamin binding proteins .
[L5545]
Passive diffusion through the intestinal wall can occur, however, high doses of vitamin B12 are required in this case (i.e. >1 mg).
After the administration of oral doses less than 3 mcg, peak plasma concentrations are not reached for 8 to 12 hours, because the vitamin is temporarily retained in the wall of the lower ileum F3736.
Orally administered vitamin B12 binds to intrinsic factor (IF) during its transport through the stomach. The separation of Vitamin B12 and IF occurs in the terminal ileum when calcium is present, and vitamin B12 is then absorbed into the gastrointestinal mucosal cells. It is then transported by transcobalamin binding proteins .
[L5545]
Passive diffusion through the intestinal wall can occur, however, high doses of vitamin B12 are required in this case (i.e. >1 mg).
After the administration of oral doses less than 3 mcg, peak plasma concentrations are not reached for 8 to 12 hours, because the vitamin is temporarily retained in the wall of the lower ileum F3736.
Half-life
Approximately 6 days (400 days in the liver) F3739.
Protein binding
Very high (to specific plasma proteins called transcobalamins); binding of hydroxocobalamin is slightly higher than cyanocobalamin [FDA label.
Volume of distribution
Cobalamin is distributed to tissues and stored mainly in the liver and bone marrow [FDA label].
Metabolism
Vitamin B12 or cyanocobalamin obtained from food is initially bound by haptocorrin, a protein found in the saliva with high affinity for B12. This forms a haptocorrin-B12 complex. Cyanocobalamin passes through the stomach and is protected from acid degradation due to its binding to haptocorrin. In the duodenum, pancreatic proteases release cobalamin from the haptocorrin-B12 complex and from other proteins containing protein-bound B12 that have been ingested.
Following this, the binding of cobalamin to a second glycoprotein, intrinsic factor, promotes its uptake by terminal ileum mucosal cells by a process called cubilin/AMN receptor-mediated endocytosis. After absorption into enterocytes, intrinsic factor is broken down in the lysosome, and cobalamin is then released into the bloodstream. The transporter ABCC1, found in the basolateral membrane of intestinal epithelial and other cells, exports cobalamin bound to transcobalamin out of the cell .
[A175273]
Cyanocobalamin then passes through the portal vein in the liver, and then reaches the systemic circulation. The active forms of cyanocobalamin are methylcobalamin and adenosylcobalamin .
[A175273], [L2064]
Following this, the binding of cobalamin to a second glycoprotein, intrinsic factor, promotes its uptake by terminal ileum mucosal cells by a process called cubilin/AMN receptor-mediated endocytosis. After absorption into enterocytes, intrinsic factor is broken down in the lysosome, and cobalamin is then released into the bloodstream. The transporter ABCC1, found in the basolateral membrane of intestinal epithelial and other cells, exports cobalamin bound to transcobalamin out of the cell .
[A175273]
Cyanocobalamin then passes through the portal vein in the liver, and then reaches the systemic circulation. The active forms of cyanocobalamin are methylcobalamin and adenosylcobalamin .
[A175273], [L2064]
Route of elimination
This drug is partially excreted in the urine F3739. According to a clinical study, approximately 3-8 mcg of vitamin B12 is secreted into the gastrointestinal tract daily via the bile. In patients with adequate levels of intrinsic factor, all except approximately 1 mcg is reabsorbed.
When vitamin B12 is administered in higher doses that saturate the binding capacity of plasma proteins and the liver, the unbound vitamin B12 is eliminated rapidly in the urine. The body storage of vitamin B12 is dose-dependent [FDA label].
When vitamin B12 is administered in higher doses that saturate the binding capacity of plasma proteins and the liver, the unbound vitamin B12 is eliminated rapidly in the urine. The body storage of vitamin B12 is dose-dependent [FDA label].
Clearance
During vitamin loading, the kidney accumulates large amounts of unbound vitamin B12. This drug is cleared partially by the kidney, however, multiligand receptor megalin promotes the reuptake and reabsorption of vitamin B12 into the body .
[A175267], [A175270]
[A175267], [A175270]
Drug targets(6)
Proteins and enzymes this drug interacts with in the body
Methionine synthase
MTR
cofactor
Specific functioncobalamin binding
Cellular location
Cytoplasm
General function & pharmacology
Catalyzes the transfer of a methyl group from methylcob(III)alamin (MeCbl) to homocysteine, yielding enzyme-bound cob(I)alamin and methionine in the cytosol .
PMID:16769880 PMID:17288554 PMID:27771510
MeCbl is an active form of cobalamin (vitamin B12) used as a cofactor for methionine biosynthesis. Cob(I)alamin form is regenerated to MeCbl by a transfer of a methyl group from 5-methyltetrahydrofolate .
PMID:16769880 PMID:17288554 PMID:27771510
The processing of cobalamin in the cytosol occurs in a multiprotein complex composed of at least MMACHC, MMADHC, MTRR (methionine synthase reductase) and MTR which may contribute to shuttle safely and efficiently cobalamin towards MTR in order to produce methionine PMID:16769880 PMID:27771510
PMID:16769880 PMID:17288554 PMID:27771510
MeCbl is an active form of cobalamin (vitamin B12) used as a cofactor for methionine biosynthesis. Cob(I)alamin form is regenerated to MeCbl by a transfer of a methyl group from 5-methyltetrahydrofolate .
PMID:16769880 PMID:17288554 PMID:27771510
The processing of cobalamin in the cytosol occurs in a multiprotein complex composed of at least MMACHC, MMADHC, MTRR (methionine synthase reductase) and MTR which may contribute to shuttle safely and efficiently cobalamin towards MTR in order to produce methionine PMID:16769880 PMID:27771510
Methylmalonyl-CoA mutase, mitochondrial
MMUT
cofactor
Specific functioncobalamin binding
Cellular location
Mitochondrion matrix
General function & pharmacology
Catalyzes the reversible isomerization of methylmalonyl-CoA (MMCoA) (generated from branched-chain amino acid metabolism and degradation of dietary odd chain fatty acids and cholesterol) to succinyl-CoA (3-carboxypropionyl-CoA), a key intermediate of the tricarboxylic acid cycle
Methionine synthase reductase
MTRR
cofactor
Specific function[methionine synthase] reductase (NADPH) activity
Cellular location
Cytoplasm
General function & pharmacology
Key enzyme in methionine and folate homeostasis responsible for the reactivation of methionine synthase (MTR/MS) activity by catalyzing the reductive methylation of MTR-bound cob(II)alamin .
PMID:17892308
Cobalamin (vitamin B12) forms a complex with MTR to serve as an intermediary in methyl transfer reactions that cycles between MTR-bound methylcob(III)alamin and MTR bound-cob(I)alamin forms, and occasional oxidative escape of the cob(I)alamin intermediate during the catalytic cycle leads to the inactive cob(II)alamin species (Probable). The processing of cobalamin in the cytosol occurs in a multiprotein complex composed of at least MMACHC, MMADHC, MTRR and MTR which may contribute to shuttle safely and efficiently cobalamin towards MTR in order to produce methionine .
PMID:27771510
Also necessary for the utilization of methyl groups from the folate cycle, thereby affecting transgenerational epigenetic inheritance (By similarity). Also acts as a molecular chaperone for methionine synthase by stabilizing apoMTR and incorporating methylcob(III)alamin into apoMTR to form the holoenzyme .
PMID:16769880
Also serves as an aquacob(III)alamin reductase by reducing aquacob(III)alamin to cob(II)alamin; this reduction leads to stimulation of the conversion of apoMTR and aquacob(III)alamin to MTR holoenzyme PMID:16769880
PMID:17892308
Cobalamin (vitamin B12) forms a complex with MTR to serve as an intermediary in methyl transfer reactions that cycles between MTR-bound methylcob(III)alamin and MTR bound-cob(I)alamin forms, and occasional oxidative escape of the cob(I)alamin intermediate during the catalytic cycle leads to the inactive cob(II)alamin species (Probable). The processing of cobalamin in the cytosol occurs in a multiprotein complex composed of at least MMACHC, MMADHC, MTRR and MTR which may contribute to shuttle safely and efficiently cobalamin towards MTR in order to produce methionine .
PMID:27771510
Also necessary for the utilization of methyl groups from the folate cycle, thereby affecting transgenerational epigenetic inheritance (By similarity). Also acts as a molecular chaperone for methionine synthase by stabilizing apoMTR and incorporating methylcob(III)alamin into apoMTR to form the holoenzyme .
PMID:16769880
Also serves as an aquacob(III)alamin reductase by reducing aquacob(III)alamin to cob(II)alamin; this reduction leads to stimulation of the conversion of apoMTR and aquacob(III)alamin to MTR holoenzyme PMID:16769880
Methylmalonic aciduria type A protein, mitochondrial
MMAA
binder
Specific functionGTP binding
Cellular location
Mitochondrion
General function & pharmacology
GTPase, binds and hydrolyzes GTP .
PMID:20876572 PMID:21138732 PMID:28497574 PMID:28943303
Involved in intracellular vitamin B12 metabolism, mediates the transport of cobalamin (Cbl) into mitochondria for the final steps of adenosylcobalamin (AdoCbl) synthesis .
PMID:20876572 PMID:28497574
Functions as a G-protein chaperone that assists AdoCbl cofactor delivery from MMAB to the methylmalonyl-CoA mutase (MMUT) .
PMID:20876572 PMID:28497574
Plays a dual role as both a protectase and a reactivase for MMUT .
PMID:21138732 PMID:28943303
Protects MMUT from progressive inactivation by oxidation by decreasing the rate of the formation of the oxidized inactive cofactor hydroxocobalamin (OH2Cbl) .
PMID:21138732 PMID:28943303
Additionally acts a reactivase by promoting the replacement of OH2Cbl by the active cofactor AdoCbl, restoring the activity of MMUT in the presence and hydrolysis of GTP PMID:21138732 PMID:28943303
PMID:20876572 PMID:21138732 PMID:28497574 PMID:28943303
Involved in intracellular vitamin B12 metabolism, mediates the transport of cobalamin (Cbl) into mitochondria for the final steps of adenosylcobalamin (AdoCbl) synthesis .
PMID:20876572 PMID:28497574
Functions as a G-protein chaperone that assists AdoCbl cofactor delivery from MMAB to the methylmalonyl-CoA mutase (MMUT) .
PMID:20876572 PMID:28497574
Plays a dual role as both a protectase and a reactivase for MMUT .
PMID:21138732 PMID:28943303
Protects MMUT from progressive inactivation by oxidation by decreasing the rate of the formation of the oxidized inactive cofactor hydroxocobalamin (OH2Cbl) .
PMID:21138732 PMID:28943303
Additionally acts a reactivase by promoting the replacement of OH2Cbl by the active cofactor AdoCbl, restoring the activity of MMUT in the presence and hydrolysis of GTP PMID:21138732 PMID:28943303
Cyanocobalamin reductase / alkylcobalamin dealkylase
MMACHC
cofactor
Specific functioncobalamin binding
Cellular location
Cytoplasm, cytosol
General function & pharmacology
Cobalamin (vitamin B12) cytosolic chaperone that catalyzes the reductive decyanation of cyanocob(III)alamin (cyanocobalamin, CNCbl) to yield cob(II)alamin and cyanide, using FAD or FMN as cofactors and NADPH as cosubstrate .
PMID:18779575 PMID:19700356 PMID:21697092 PMID:25809485
Cyanocobalamin constitutes the inactive form of vitamin B12 introduced from the diet, and is converted into the active cofactors methylcobalamin (MeCbl) involved in methionine biosynthesis, and 5'-deoxyadenosylcobalamin (AdoCbl) involved in the TCA cycle .
PMID:19801555
Forms a complex with the lysosomal transporter ABCD4 and its chaperone LMBRD1, to transport cobalamin across the lysosomal membrane into the cytosol .
PMID:25535791
The processing of cobalamin in the cytosol occurs in a multiprotein complex composed of at least MMACHC, MMADHC, MTRR (methionine synthase reductase) and MTR (methionine synthase) which may contribute to shuttle safely and efficiently cobalamin towards MTR in order to produce methionine .
PMID:21071249 PMID:27771510
Also acts as a glutathione transferase by catalyzing the dealkylation of the alkylcob(III)alamins MeCbl and AdoCbl, using the thiolate of glutathione for nucleophilic displacement to generate cob(I)alamin and the corresponding glutathione thioether .
PMID:19801555 PMID:21697092 PMID:22642810 PMID:25809485
The conversion of incoming MeCbl or AdoCbl into a common intermediate cob(I)alamin is necessary to meet the cellular needs for both cofactors .
PMID:19801555
Cysteine and homocysteine cannot substitute for glutathione in this reaction PMID:19801555
PMID:18779575 PMID:19700356 PMID:21697092 PMID:25809485
Cyanocobalamin constitutes the inactive form of vitamin B12 introduced from the diet, and is converted into the active cofactors methylcobalamin (MeCbl) involved in methionine biosynthesis, and 5'-deoxyadenosylcobalamin (AdoCbl) involved in the TCA cycle .
PMID:19801555
Forms a complex with the lysosomal transporter ABCD4 and its chaperone LMBRD1, to transport cobalamin across the lysosomal membrane into the cytosol .
PMID:25535791
The processing of cobalamin in the cytosol occurs in a multiprotein complex composed of at least MMACHC, MMADHC, MTRR (methionine synthase reductase) and MTR (methionine synthase) which may contribute to shuttle safely and efficiently cobalamin towards MTR in order to produce methionine .
PMID:21071249 PMID:27771510
Also acts as a glutathione transferase by catalyzing the dealkylation of the alkylcob(III)alamins MeCbl and AdoCbl, using the thiolate of glutathione for nucleophilic displacement to generate cob(I)alamin and the corresponding glutathione thioether .
PMID:19801555 PMID:21697092 PMID:22642810 PMID:25809485
The conversion of incoming MeCbl or AdoCbl into a common intermediate cob(I)alamin is necessary to meet the cellular needs for both cofactors .
PMID:19801555
Cysteine and homocysteine cannot substitute for glutathione in this reaction PMID:19801555
Metabolizing enzymes(1)
Enzymes involved in drug metabolism — important for understanding drug interactions
Enzyme activity key
substrate
inhibitor
inducer
MMABCorrinoid adenosyltransferase MMAB
substrate
Transporters(7)
Proteins that transport this drug across cell membranes
Protein amnionless
AMN
substrate
Specific functioncargo receptor activity
Cellular location
Apical cell membrane
General function & pharmacology
Membrane-bound component of the endocytic receptor formed by AMN and CUBN .
PMID:14576052 PMID:29402915 PMID:30523278
Required for normal CUBN glycosylation and trafficking to the cell surface .
PMID:14576052 PMID:29402915
The complex formed by AMN and CUBN is required for efficient absorption of vitamin B12 .
PMID:12590260 PMID:14576052 PMID:26040326
Required for normal CUBN-mediated protein transport in the kidney (Probable)
PMID:14576052 PMID:29402915 PMID:30523278
Required for normal CUBN glycosylation and trafficking to the cell surface .
PMID:14576052 PMID:29402915
The complex formed by AMN and CUBN is required for efficient absorption of vitamin B12 .
PMID:12590260 PMID:14576052 PMID:26040326
Required for normal CUBN-mediated protein transport in the kidney (Probable)
Transcobalamin-1
TCN1
substrate
Specific functioncargo receptor ligand activity
Cellular location
Secreted
General function & pharmacology
Binds vitamin B12 with femtomolar affinity and protects it from the acidic environment of the stomach
Transcobalamin-2
TCN2
substrate
Specific functioncargo receptor ligand activity
Cellular location
Secreted
General function & pharmacology
Primary vitamin B12-binding and transport protein. Delivers cobalamin to cells
Cobalamin binding intrinsic factor
CBLIF
substrate
Specific functioncargo receptor ligand activity
Cellular location
Secreted
General function & pharmacology
Promotes absorption of the essential vitamin cobalamin (Cbl) in the ileum. After interaction with CUBN, the CBLIF-cobalamin complex is internalized via receptor-mediated endocytosis
Cubilin
CUBN
substrate
Specific functioncalcium ion binding
Cellular location
Apical cell membrane
General function & pharmacology
Endocytic receptor which plays a role in lipoprotein, vitamin and iron metabolism by facilitating their uptake .
PMID:10371504 PMID:11606717 PMID:11717447 PMID:14576052 PMID:9572993
Acts together with LRP2 to mediate endocytosis of high-density lipoproteins, GC, hemoglobin, ALB, TF and SCGB1A1. Acts together with AMN to mediate endocytosis of the CBLIF-cobalamin complex .
PMID:14576052 PMID:9572993
Binds to ALB, MB, Kappa and lambda-light chains, TF, hemoglobin, GC, SCGB1A1, APOA1, high density lipoprotein, and the CBLIF-cobalamin complex. Ligand binding requires calcium .
PMID:9572993
Serves as important transporter in several absorptive epithelia, including intestine, renal proximal tubules and embryonic yolk sac.
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
PMID:10371504 PMID:11606717 PMID:11717447 PMID:14576052 PMID:9572993
Acts together with LRP2 to mediate endocytosis of high-density lipoproteins, GC, hemoglobin, ALB, TF and SCGB1A1. Acts together with AMN to mediate endocytosis of the CBLIF-cobalamin complex .
PMID:14576052 PMID:9572993
Binds to ALB, MB, Kappa and lambda-light chains, TF, hemoglobin, GC, SCGB1A1, APOA1, high density lipoprotein, and the CBLIF-cobalamin complex. Ligand binding requires calcium .
PMID:9572993
Serves as important transporter in several absorptive epithelia, including intestine, renal proximal tubules and embryonic yolk sac.
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
Low-density lipoprotein receptor-related protein 2
LRP2
Specific functioncalcium ion binding
Cellular location
Apical cell membrane
General function & pharmacology
Multiligand endocytic receptor (By similarity). Acts together with CUBN to mediate endocytosis of high-density lipoproteins (By similarity). Mediates receptor-mediated uptake of polybasic drugs such as aprotinin, aminoglycosides and polymyxin B (By similarity).
In the kidney, mediates the tubular uptake and clearance of leptin (By similarity). Also mediates transport of leptin across the blood-brain barrier through endocytosis at the choroid plexus epithelium (By similarity). Endocytosis of leptin in neuronal cells is required for hypothalamic leptin signaling and leptin-mediated regulation of feeding and body weight (By similarity).
Mediates endocytosis and subsequent lysosomal degradation of CST3 in kidney proximal tubule cells (By similarity). Mediates renal uptake of 25-hydroxyvitamin D3 in complex with the vitamin D3 transporter GC/DBP (By similarity). Mediates renal uptake of metallothionein-bound heavy metals .
PMID:15126248
Together with CUBN, mediates renal reabsorption of myoglobin (By similarity).
Mediates renal uptake and subsequent lysosomal degradation of APOM (By similarity). Plays a role in kidney selenium homeostasis by mediating renal endocytosis of selenoprotein SEPP1 (By similarity). Mediates renal uptake of the antiapoptotic protein BIRC5/survivin which may be important for functional integrity of the kidney .
PMID:23825075
Mediates renal uptake of matrix metalloproteinase MMP2 in complex with metalloproteinase inhibitor TIMP1 (By similarity).
Mediates endocytosis of Sonic hedgehog protein N-product (ShhN), the active product of SHH (By similarity). Also mediates ShhN transcytosis (By similarity). In the embryonic neuroepithelium, mediates endocytic uptake and degradation of BMP4, is required for correct SHH localization in the ventral neural tube and plays a role in patterning of the ventral telencephalon (By similarity).
Required at the onset of neurulation to sequester SHH on the apical surface of neuroepithelial cells of the rostral diencephalon ventral midline and to control PTCH1-dependent uptake and intracellular trafficking of SHH (By similarity). During neurulation, required in neuroepithelial cells for uptake of folate bound to the folate receptor FOLR1 which is necessary for neural tube closure (By similarity). In the adult brain, negatively regulates BMP signaling in the subependymal zone which enables neurogenesis to proceed (By similarity).
In astrocytes, mediates endocytosis of ALB which is required for the synthesis of the neurotrophic factor oleic acid (By similarity). Involved in neurite branching (By similarity). During optic nerve development, required for SHH-mediated migration and proliferation of oligodendrocyte precursor cells (By similarity).
Mediates endocytic uptake and clearance of SHH in the retinal margin which protects retinal progenitor cells from mitogenic stimuli and keeps them quiescent (By similarity). Plays a role in reproductive organ development by mediating uptake in reproductive tissues of androgen and estrogen bound to the sex hormone binding protein SHBG (By similarity). Mediates endocytosis of angiotensin-2 (By similarity).
Also mediates endocytosis of angiotensis 1-7 (By similarity). Binds to the complex composed of beta-amyloid protein 40 and CLU/APOJ and mediates its endocytosis and lysosomal degradation (By similarity). Required for embryonic heart development (By similarity).
Required for normal hearing, possibly through interaction with estrogen in the inner ear (By similarity)
In the kidney, mediates the tubular uptake and clearance of leptin (By similarity). Also mediates transport of leptin across the blood-brain barrier through endocytosis at the choroid plexus epithelium (By similarity). Endocytosis of leptin in neuronal cells is required for hypothalamic leptin signaling and leptin-mediated regulation of feeding and body weight (By similarity).
Mediates endocytosis and subsequent lysosomal degradation of CST3 in kidney proximal tubule cells (By similarity). Mediates renal uptake of 25-hydroxyvitamin D3 in complex with the vitamin D3 transporter GC/DBP (By similarity). Mediates renal uptake of metallothionein-bound heavy metals .
PMID:15126248
Together with CUBN, mediates renal reabsorption of myoglobin (By similarity).
Mediates renal uptake and subsequent lysosomal degradation of APOM (By similarity). Plays a role in kidney selenium homeostasis by mediating renal endocytosis of selenoprotein SEPP1 (By similarity). Mediates renal uptake of the antiapoptotic protein BIRC5/survivin which may be important for functional integrity of the kidney .
PMID:23825075
Mediates renal uptake of matrix metalloproteinase MMP2 in complex with metalloproteinase inhibitor TIMP1 (By similarity).
Mediates endocytosis of Sonic hedgehog protein N-product (ShhN), the active product of SHH (By similarity). Also mediates ShhN transcytosis (By similarity). In the embryonic neuroepithelium, mediates endocytic uptake and degradation of BMP4, is required for correct SHH localization in the ventral neural tube and plays a role in patterning of the ventral telencephalon (By similarity).
Required at the onset of neurulation to sequester SHH on the apical surface of neuroepithelial cells of the rostral diencephalon ventral midline and to control PTCH1-dependent uptake and intracellular trafficking of SHH (By similarity). During neurulation, required in neuroepithelial cells for uptake of folate bound to the folate receptor FOLR1 which is necessary for neural tube closure (By similarity). In the adult brain, negatively regulates BMP signaling in the subependymal zone which enables neurogenesis to proceed (By similarity).
In astrocytes, mediates endocytosis of ALB which is required for the synthesis of the neurotrophic factor oleic acid (By similarity). Involved in neurite branching (By similarity). During optic nerve development, required for SHH-mediated migration and proliferation of oligodendrocyte precursor cells (By similarity).
Mediates endocytic uptake and clearance of SHH in the retinal margin which protects retinal progenitor cells from mitogenic stimuli and keeps them quiescent (By similarity). Plays a role in reproductive organ development by mediating uptake in reproductive tissues of androgen and estrogen bound to the sex hormone binding protein SHBG (By similarity). Mediates endocytosis of angiotensin-2 (By similarity).
Also mediates endocytosis of angiotensis 1-7 (By similarity). Binds to the complex composed of beta-amyloid protein 40 and CLU/APOJ and mediates its endocytosis and lysosomal degradation (By similarity). Required for embryonic heart development (By similarity).
Required for normal hearing, possibly through interaction with estrogen in the inner ear (By similarity)
Multidrug resistance-associated protein 1
ABCC1
Specific functionABC-type glutathione S-conjugate transporter activity
Cellular location
Cell membrane
General function & pharmacology
Mediates export of organic anions and drugs from the cytoplasm .
PMID:10064732 PMID:11114332 PMID:16230346 PMID:7961706 PMID:9281595
Mediates ATP-dependent transport of glutathione and glutathione conjugates, leukotriene C4, estradiol-17-beta-o-glucuronide, methotrexate, antiviral drugs and other xenobiotics .
PMID:10064732 PMID:11114332 PMID:16230346 PMID:7961706 PMID:9281595
Confers resistance to anticancer drugs by decreasing accumulation of drug in cells, and by mediating ATP- and GSH-dependent drug export .
PMID:9281595
Hydrolyzes ATP with low efficiency .
PMID:16230346
Catalyzes the export of sphingosine 1-phosphate from mast cells independently of their degranulation .
PMID:17050692
Participates in inflammatory response by allowing export of leukotriene C4 from leukotriene C4-synthesizing cells (By similarity). Mediates ATP-dependent, GSH-independent cyclic GMP-AMP (cGAMP) export .
PMID:36070769
Thus, by limiting intracellular cGAMP concentrations negatively regulates the cGAS-STING pathway .
PMID:36070769
Exports S-geranylgeranyl-glutathione (GGG) in lymphoid cells and stromal compartments of lymphoid organs. ABCC1 (via extracellular transport) with GGT5 (via GGG catabolism) establish GGG gradients within lymphoid tissues to position P2RY8-positive lymphocytes at germinal centers in lymphoid follicles and restrict their chemotactic transmigration from blood vessels to the bone marrow parenchyma (By similarity).
Mediates basolateral export of GSH-conjugated R- and S-prostaglandin A2 diastereomers in polarized epithelial cells PMID:9426231
PMID:10064732 PMID:11114332 PMID:16230346 PMID:7961706 PMID:9281595
Mediates ATP-dependent transport of glutathione and glutathione conjugates, leukotriene C4, estradiol-17-beta-o-glucuronide, methotrexate, antiviral drugs and other xenobiotics .
PMID:10064732 PMID:11114332 PMID:16230346 PMID:7961706 PMID:9281595
Confers resistance to anticancer drugs by decreasing accumulation of drug in cells, and by mediating ATP- and GSH-dependent drug export .
PMID:9281595
Hydrolyzes ATP with low efficiency .
PMID:16230346
Catalyzes the export of sphingosine 1-phosphate from mast cells independently of their degranulation .
PMID:17050692
Participates in inflammatory response by allowing export of leukotriene C4 from leukotriene C4-synthesizing cells (By similarity). Mediates ATP-dependent, GSH-independent cyclic GMP-AMP (cGAMP) export .
PMID:36070769
Thus, by limiting intracellular cGAMP concentrations negatively regulates the cGAS-STING pathway .
PMID:36070769
Exports S-geranylgeranyl-glutathione (GGG) in lymphoid cells and stromal compartments of lymphoid organs. ABCC1 (via extracellular transport) with GGT5 (via GGG catabolism) establish GGG gradients within lymphoid tissues to position P2RY8-positive lymphocytes at germinal centers in lymphoid follicles and restrict their chemotactic transmigration from blood vessels to the bone marrow parenchyma (By similarity).
Mediates basolateral export of GSH-conjugated R- and S-prostaglandin A2 diastereomers in polarized epithelial cells PMID:9426231
Scientific references(16)
Wickramasinghe S.N.
1 Morphology, biology and biochemistry of cobalamin- and folate-deficient bone marrow cells.
Baillière's Clinical Haematology
19958(3):441-459. doi: 10.1016/s0950-3536(05)80215-x
Sharabi A., Cohen E., Sulkes J., Garty M.
Replacement therapy for vitamin B12 deficiency: comparison between the sublingual and oral route.
British Journal of Clinical Pharmacology
200356(6):635-638. doi: 10.1046/j.1365-2125.2003.01907.x
Hall A.H., Rumack B.H.
Hydroxycobalamin/sodium thiosulfate as a cyanide antidote.
The Journal of Emergency Medicine
19875(2):115-121. doi: 10.1016/0736-4679(87)90074-6
Andres E., Noel E., Goichot B.
Metformin-Associated Vitamin B12 Deficiency.
Archives of Internal Medicine
2002162(19):2251. doi: 10.1001/archinte.162.19.2251-a
Gilligan M.A.
Metformin and Vitamin B12 Deficiency.
Archives of Internal Medicine
2002162(4):484. doi: 10.1001/archinte.162.4.484
Bonaa K.H., Njolstad I., Ueland P.M., Schirmer H., Tverdal A., Steigen T., Wang H., Nordrehaug J.E., Arnesen E., Rasmussen K.
Homocysteine lowering and cardiovascular events after acute myocardial infarction.
New England Journal of Medicine
2006 Apr 13354(15):1578-88. doi: 10.1056/NEJMoa055227. Epub 2006 Mar 12
Lonn E., Yusuf S., Arnold M.J., Sheridan P., Pogue J., Micks M., McQueen M.J., Probstfield J., Fodor G., Held C., Genest J Jr
Homocysteine lowering with folic acid and B vitamins in vascular disease.
New England Journal of Medicine
2006 Apr 13354(15):1567-77. doi: 10.1056/NEJMoa060900. Epub 2006 Mar 12
Russell-Jones G.J., Alpers D.H.
Vitamin B12 Transporters. Pharmaceutical Biotechnology. :493-520.
doi: 10
1007/0-306-46812-3_17
Seetharam B.
Receptor-mediated endocytosis of cobalamin (vitamin B12).
Annual Review Nutr
199919:173-95. doi: 10.1146/annurev.nutr.19.1.173
O'Leary F., Samman S.
Vitamin B12 in health and disease.
Nutrients
2010 Mar2(3):299-316. doi: 10.3390/nu2030299. Epub 2010 Mar 5
Scott J.M.
Folate and vitamin B<sub>12</sub>.
Proceedings of the Nutrition Society
199958(2):441-448. doi: 10.1017/s0029665199000580
Zhang M., Han W., Hu S., Xu H.
Methylcobalamin: a potential vitamin of pain killer.
Neural Plast
20132013:424651. doi: 10.1155/2013/424651. Epub 2013 Dec 26
Birn H.
The kidney in vitamin B12 and folate homeostasis: characterization of receptors for tubular uptake of vitamins and carrier proteins.
American Journal Physiology Renal Physiology
2006 Jul291(1):F22-36. doi: 10.1152/ajprenal.00385.2005
Moestrup S.K., Birn H., Fischer P.B., Petersen C.M., Verroust P.J., Sim R.B., Christensen E.I., Nexo E.
Megalin-mediated endocytosis of transcobalamin-vitamin-B12 complexes suggests a role of the receptor in vitamin-B12 homeostasis..
Proceedings of the National Academy of Sciences
199693(16):8612-8617. doi: 10.1073/pnas.93.16.8612
Gherasim C., Lofgren M., Banerjee R.
Navigating the B(12) road: assimilation, delivery, and disorders of cobalamin.
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ATC classification(2 codes)
ATC B03BA01
ATC B03BA51
Affected organisms(1)
Humans and other mammals
International brands(15)
Experimental properties(6)
Commercial products(1463)
Chemical identifiers
CAS, UNII, InChI Key and database cross-references
Show
Chemical identifiers
CAS, UNII, InChI Key and database cross-references
Linked compound data from DrugBank Open Data (CC BY-NC 4.0)
Cyanocobalamin
Additional database identifiers
Drugs Product Database (DPD)
781
Drugs Product Database (DPD)
4821
Drugs Product Database (DPD)
4991
ChemSpider
21864832
PDB
CNC
HUGO Gene Nomenclature Committee (HGNC)
HGNC:7468
GenAtlas
MTR
GeneCards
MTR
GenBank Gene Database
U71285
GenBank Protein Database
1923221
UniProt Accession
METH_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:7526
GenAtlas
MUT
GeneCards
MMUT
GenBank Gene Database
M65131
GenBank Protein Database
187452
UniProt Accession
MUTA_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:7473
GenAtlas
MTRR
GeneCards
MTRR
GenBank Gene Database
AF121213
GenBank Protein Database
6572540
UniProt Accession
MTRR_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:18871
GenAtlas
MMAA
GeneCards
MMAA
GenBank Gene Database
AF524846
GenBank Protein Database
26006421
UniProt Accession
MMAA_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:24525
GenAtlas
MMACHC
GeneCards
MMACHC
GenBank Gene Database
AL080062
GenBank Protein Database
52545527
UniProt Accession
MMAC_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:7436
GenAtlas
MTHFR
GeneCards
MTHFR
GenBank Gene Database
U09806
GenBank Protein Database
6139053
UniProt Accession
MTHR_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:19331
GenAtlas
MMAB
GeneCards
MMAB
GenBank Gene Database
AF550404
GenBank Protein Database
26284726
UniProt Accession
MMAB_HUMAN
GenBank Gene Database
AE008789
UniProt Accession
COBU_SALTY
HUGO Gene Nomenclature Committee (HGNC)
HGNC:14604
GenAtlas
AMN
GeneCards
AMN
GenBank Gene Database
AF328788
GenBank Protein Database
13507259
UniProt Accession
AMNLS_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:11652
GenAtlas
TCN1
GeneCards
TCN1
GenBank Gene Database
J05068
GenBank Protein Database
307479
UniProt Accession
TCO1_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:11653
GenAtlas
TCN2
GeneCards
TCN2
GenBank Gene Database
M60396
GenBank Protein Database
339196
UniProt Accession
TCO2_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:4268
GeneCards
CBLIF
UniProt Accession
IF_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2548
GenAtlas
CUBN
GeneCards
CUBN
GenBank Gene Database
AF034611
GenBank Protein Database
3929529
UniProt Accession
CUBN_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:6694
GenAtlas
LRP2
GeneCards
LRP2
GenBank Gene Database
U33837
GenBank Protein Database
1809240
UniProt Accession
LRP2_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:51
GenAtlas
ABCC1
GeneCards
ABCC1
GenBank Gene Database
L05628
GenBank Protein Database
1835659
Guide to Pharmacology
779
UniProt Accession
MRP1_HUMAN
International reference pricing
26 formulations
Reference pricing from DrugBank. Prices are indicative and may not reflect current UK costs.
From $0.02/tablet
To $277.97/bottle
Pv b-12 250 mcg tablet
$0.02/tablet
Vitamin b-12 100 mcg tablet
$0.02/tablet
CVS Pharmacy vitamin b12 100 mcg tablet
$0.03/tablet
Pv vit b-12 1000 mcg tablet sl
$0.03/tablet
Ra vitamin b-12 50 mcg tablet
$0.03/tablet
Source: DrugBank. Used under CC BY-NC 4.0 academic licence for non-commercial purposes.
Patent information
All patents expired, 6 expired
7229636
United States
Approved 12 Jun 2007 · Expires 1 Aug 2024
Expired
7879349
United States
Approved 1 Feb 2011 · Expires 1 Aug 2024
Expired
8003353
United States
Approved 23 Aug 2011 · Expires 1 Aug 2024
Expired
9415007
United States
Approved 16 Aug 2016 · Expires 28 Jul 2024
Expired
7404489
United States
Approved 29 Jul 2008 · Expires 12 Mar 2024
Expired
Patent protection has expired — generic versions may be available.
Source: DrugBank · CC BY-NC 4.0. Patent data sourced from national patent offices. Expiry dates may not reflect extensions, regulatory exclusivity periods, or legal challenges.
DrugBank citations
If you use DrugBank data in your research, please cite the following publications:
Knox C., Wilson M., Klinger C.M., et al
DrugBank 6.
0: the DrugBank Knowledgebase for 2024
Nucleic Acids Res. 2024 Jan 552(D1):D1265-D1275
Wishart D.S., Feunang Y.D., Guo A.C., et al
DrugBank 5.
0: a major update to the DrugBank database for 2018
Nucleic Acids Res. 2017 Nov 846(D1):D1074-D1082
Show earlier publications
Law V., Knox C., Djoumbou Y., et al
DrugBank 4.
0: shedding new light on drug metabolism
Nucleic Acids Res. 2014 Jan 142(1):D1091-7
Knox C., Law V., Jewison T., et al
DrugBank 3.
0: a comprehensive resource for 'omics' research on drugs
Nucleic Acids Res. 2011 Jan39(Database issue):D1035-41
Wishart D.S., Knox C., Guo A.C., et al
DrugBank: a knowledgebase for drugs, drug actions and drug targets.
Nucleic Acids Research
2008 Jan36(Database issue):D901-6
Wishart D.S., Knox C., Guo A.C., et al
DrugBank: a comprehensive resource for in silico drug discovery and exploration.
Nucleic Acids Research
2006 Jan 134(Database issue):D668-72
Source: go.drugbank.comCC BY-NC 4.0
Updated 26 days ago(8 Mar 2026)