Vitamin B12 (Adenosylcobalamin)
Also known as: dibencozide, cobamamide, AdoCbl, 5'-deoxyadenosylcobalamin, coenzyme B12
Adenosylcobalamin is the mitochondrial coenzyme form of vitamin B12, required by methylmalonyl-CoA mutase to feed odd-chain fatty acids and certain amino acids into the citric acid cycle. NIH ODS lists it with methylcobalamin as one of the two metabolically active cobalamins. It is a niche supplement form, usually combined with methylcobalamin in premium B12 or mitochondrial-energy products, and cells interconvert the cobalamin forms, so it is not required separately to cover the mutase pathway. No UL exists.
Research summary
Cofactor for methylmalonyl-CoA mutase in mitochondria, converting methylmalonyl-CoA to succinyl-CoA; interconverted intracellularly with methylcobalamin.
Dosage
Daily amounts, of compound.
| Lowest studied | Typical range | Highest studied | Upper limit |
|---|---|---|---|
| 2 mcg | 100–1,000 mcg | — | — |
Doses are mcg adenosylcobalamin. RDA 2.4 mcg; DV 2.4 mcg; no UL. Products use the same 100 to 1,000 mcg range as other B12 forms, often split with methylcobalamin; no dose-ranging trial specific to oral adenosylcobalamin was verified, so dose_max_studied is left unset. Light-sensitive; store protected.
Standardization: ≥98% adenosylcobalamin or 1% trituration
Source material: semi-synthetic from fermentation-derived cobalamin
As supplied: Typically a 1% trituration on a carrier (0.1 mg powder per mcg)
Forms of Vitamin B12
| Form | Typical dose | Element % | Formats | Price |
|---|---|---|---|---|
| Vitamin B12 (Adenosylcobalamin) | 100–1,000 mcg | — | Capsule, Tablet, Powder, Liquid | high |
| Vitamin B12 (Cyanocobalamin) | 100–1,000 mcg | — | Capsule, Tablet, Powder, Gummy, Liquid, Softgel | low |
| Vitamin B12 (Methylcobalamin) | 100–1,000 mcg | — | Capsule, Tablet, Powder, Liquid, Gummy | mid |
Format suitability
- Capsule
- Powder
- Tablet
- Softgel
- Gummy
- Liquid
Light- and heat-sensitive; avoid gummies and hot-process formats without stability data.
Formulation notes
Usually paired with methylcobalamin. Same metformin and acid-suppressant considerations as other B12 forms.
Sources
Related ingredients
Vitamin B12 (Cyanocobalamin)
VitaminCyanocobalamin is the synthetic, highly stable form of vitamin B12 used in most supplements and fortified foods.
Typical: 100–1,000 mcg
Vitamin B12 (Methylcobalamin)
VitaminMethylcobalamin is one of the two coenzyme forms of vitamin B12 that the body uses directly, in this case for the methionine synthase reaction that recycles homocysteine and supports methylation.
Typical: 100–1,000 mcg
Iron Bisglycinate
MineralFerrous iron chelated with two glycine molecules, the form most prenatal and gentle-iron products now use.
Typical: 18–30 mg
Vitamin B6 (Pyridoxine HCl)
VitaminPyridoxine hydrochloride is the standard, inexpensive, and highly stable form of vitamin B6 used in nearly all multivitamins and B-complex products.
Typical: 1.7–50 mg
Iron (Ferrous Sulfate)
MineralThe reference iron salt used in most clinical research and public-health programs, inexpensive and reliably absorbed.
Typical: 18–45 mg