Vitamin B12 (Cyanocobalamin)
Also known as: cyanocobalamin, vitamin B12, cobalamin, B12
Cyanocobalamin is the synthetic, highly stable form of vitamin B12 used in most supplements and fortified foods. NIH ODS notes it becomes active after conversion to methylcobalamin and adenosylcobalamin, the two coenzyme forms. Vitamin B12 is needed for red blood cell formation, nerve myelin, and homocysteine metabolism, and oral doses of 1,000 to 2,000 mcg have matched injections in trials on deficient patients, because a small fraction is absorbed passively even without intrinsic factor. No UL exists.
Research summary
Reduced and decyanated in cells to cob(II)alamin, then converted to methylcobalamin (methionine synthase) and adenosylcobalamin (methylmalonyl-CoA mutase).
Dosage
Daily amounts, of compound.
| Lowest studied | Typical range | Highest studied | Upper limit |
|---|---|---|---|
| 2 mcg | 100–1,000 mcg | 2,000 mcg | — |
Doses are mcg cyanocobalamin. RDA is 2.4 mcg for adults; DV 2.4 mcg. NIH ODS reports no UL because B12 is considered safe even at high doses. A systematic review of randomized trials compared oral 2,000 mcg daily (and 1,000 mcg regimens) with intramuscular B12 in deficient patients and found oral dosing effective. Absorption via intrinsic factor saturates at a few mcg per dose, so high oral doses rely on passive uptake; take without regard to meals. Stable to heat and light better than other cobalamins.
Standardization: ≥96% cyanocobalamin (USP) or 0.1% to 1% trituration
Source material: fermentation (Pseudomonas or Propionibacterium), purified
As supplied: Typically a 1% trituration on a carrier (0.1 mg powder per mcg); 0.1% grades are used for very low doses
Forms of Vitamin B12
| Form | Typical dose | Element % | Formats | Price |
|---|---|---|---|---|
| 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 |
| Vitamin B12 (Adenosylcobalamin) | 100–1,000 mcg | — | Capsule, Tablet, Powder, Liquid | high |
Format suitability
- Capsule
- Powder
- Tablet
- Softgel
- Gummy
- Liquid
Deep red; tints powders and liquids pink at high inclusion. Most stable B12 for gummies and liquids.
Formulation notes
Pair with folate in any formula above 400 mcg folic acid. Metformin and acid-suppressing drugs lower B12 status. Degraded by vitamin C in solution over time.
Sources
Related ingredients
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
Folic Acid
VitaminFolic acid is the fully oxidized, synthetic form of folate used in food fortification and most supplements.
Typical: 400–800 mcg
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
L-5-Methyltetrahydrofolate (L-5-MTHF)
VitaminL-5-methyltetrahydrofolate is the main circulating form of folate and the form cells use directly for homocysteine remethylation, so it bypasses the MTHFR enzyme step that is less active in people carrying the common 677C>T variant.
Typical: 400–1,000 mcg
Thiamin HCl (Vitamin B1)
VitaminThiamin hydrochloride is one of the two standard water-soluble salts of vitamin B1 used in supplements (the other is the mononitrate).
Typical: 1.5–100 mg