Vitamin B12

Compound	Vitamin B12 (cobalamin)
Chemical class	Corrinoid — cobalt-centred tetrapyrrole; forms include methyl-, adenosyl-, hydroxo- and cyanocobalamin
CAS	68-19-9 (cyanocobalamin) · 13422-55-4 (methylcobalamin)
Primary source	Bacterial fermentation for isolated grades; Chlorella vulgaris for algal food-matrix grades
Key applications	Haematopoiesis, myelin maintenance, homocysteine metabolism, energy metabolism in deficiency
Claim strength	High for deficiency correction; Moderate to Emerging for everything else
Typical form	0.1–1% trituration on a carrier, algal concentrate, or liposomal powder
Buy from Herbuno	Vitamin B12 from Chlorella vulgaris · Liposomal Vitamin B12 (Methylcobalamin)
Origin	Processed / Sourced from India
MOQ	R&D 100 g / 250 g (subject to stock) · Pilot batch 1–5 kg · Bulk 10 kg, 25 kg and above
Lead Time	Dispatch within 72 hrs from stock · fresh-batch production (typically 50 kg+): 10 working days
Documentation	CoA & MSDS standard with every lot; phytosanitary on request

Name origin: Cobalamin is named for the cobalt atom at the centre of its corrin ring — the only vitamin containing a metal ion, and the only one that no plant or animal can synthesise. It is made exclusively by bacteria and archaea. Everything else in the food chain acquires it by eating microbes, by harbouring them, or by eating animals that did. The number 12 is a remnant of the B-complex numbering, most of which was later reassigned when compounds turned out not to be vitamins at all.

Traditional use: There is no traditional use, because the deficiency disease was uniformly fatal and its cure was accidental. Pernicious anaemia was described in 1849 and killed reliably until 1926, when Minot and Murphy found that feeding patients around half a kilogram of raw or lightly cooked liver daily produced remission. They had no idea why; the active factor was not isolated until 1948 and not structurally solved until Dorothy Hodgkin's crystallographic work in 1956, which won her the Nobel Prize.

Research trajectory: Once the molecule was characterised the field divided into three questions, and only the first is settled. Deficiency correction works and the evidence is unambiguous. Whether one cobalamin form is clinically superior to another remains unresolved despite confident marketing on both sides. And whether lowering homocysteine with B12 and folate reduces cardiovascular or cognitive events has been tested repeatedly in large trials and has mostly come back null, despite homocysteine falling as expected — the same biomarker-versus-outcome gap seen with vitamin D.

Commercial source: Essentially all isolated B12 is produced by bacterial fermentation, typically Pseudomonas denitrificans or Propionibacterium species, then purified and crystallised. Cyanocobalamin is the most stable crystalline form and dominates supply. Algal grades are a different proposition: the alga is grown, dried and extracted, giving a food-matrix B12 with a declared assay. This is the route with the largest quality variance in the category, because many algal materials contain corrinoid analogues that register on some assays without being usable by humans.

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Evidence for Vitamin B12 Applications

The pseudo-B12 problem is the single most important technical fact in this category and it separates Chlorella from Spirulina decisively. Spirulina contains predominantly pseudovitamin B12, a corrinoid analogue that is inactive in humans but which registers on microbiological assays, meaning a Spirulina material can carry a credible-looking B12 number and deliver essentially nothing. Chlorella vulgaris is different: methylcobalamin has been identified and characterised in it directly. [Watanabe 2014] A formulator sourcing algal B12 must know which alga and must see an assay method that distinguishes true cobalamin from analogues. Treating "algal B12" as a single category is the error that produces non-functional vegan products. Claim strength: High.

Deficiency correction is unambiguous and the at-risk groups are well defined. Vegans and long-term vegetarians lack a dietary source entirely; adults over about fifty lose gastric acid and intrinsic factor production, impairing absorption from food even when intake is adequate; metformin and long-term proton pump inhibitor use both reduce absorption. Correction reverses megaloblastic anaemia reliably and prevents the neurological damage of subacute combined degeneration, which becomes irreversible if left too long. For a largely vegetarian population such as India's, this is not a marginal supplement category but a primary one. Claim strength: High.

Methylcobalamin versus cyanocobalamin is marketed as settled and is not. Methylcobalamin is a coenzyme form requiring no conversion, which is mechanistically appealing; cyanocobalamin is more stable, better characterised in trials, and must shed a cyanide moiety that is trivial at nutritional doses. Head-to-head human data comparing the two at matched doses for correcting deficiency are limited, and what exists does not establish clear superiority for either. Methylcobalamin may be preferable in specific circumstances such as renal impairment where cyanide clearance is a genuine consideration. Paying a premium for methylcobalamin on bioavailability grounds alone is not well supported. Claim strength: Moderate.

Homocysteine lowering is real; the outcome benefit is not demonstrated. B12 with folate and B6 reliably reduces plasma homocysteine, and elevated homocysteine is associated with cardiovascular disease and cognitive decline in observational data. Large randomised trials testing whether lowering it changes those outcomes have largely been null for cardiovascular events. Some cognitive trials in subgroups with elevated homocysteine and adequate omega-3 status have shown signals on brain atrophy rates, which is interesting but not a general claim. Products should not imply that lowering a marker delivers the outcome the marker predicts. Claim strength: Emerging.

Absorption is the rate-limiting step and it caps what a dose can achieve. The intrinsic factor pathway saturates at roughly 1.5 to 2 micrograms per dose; above that, uptake continues only by passive diffusion at around 1% of the administered amount. This is why high-dose oral B12 works at all for people lacking intrinsic factor — 1,000 micrograms orally delivers perhaps 10 micrograms passively, which is sufficient. It also explains why very large oral doses are not proportionally more effective, and why dosing frequency can matter more than dose size for people with functioning absorption. Claim strength: High.

B12 has no established upper limit and no meaningful toxicity at supplemental doses, which is a genuine advantage in formulation. EFSA and the US Institute of Medicine have both declined to set a tolerable upper intake level, citing absence of adverse effects from high intake in healthy people. Excess is excreted renally. The practical constraints are therefore cost, stability and label credibility rather than safety. Elevated serum B12 can occasionally be a marker of underlying disease, but that is a diagnostic signal rather than a consequence of supplementation. Claim strength: High.

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Dosage & Formulator Specification

Pure cobalamin is active at microgram level, so it is never supplied neat for formulation. Commercial material is a trituration — commonly 0.1% or 1% cobalamin on a mannitol, dicalcium phosphate or starch carrier — and the declared percentage is what you dose against. A 1% trituration delivers 10 micrograms per milligram of powder, so a 500 microgram dose needs 50 mg of material. Algal grades are declared differently again, as micrograms of B12 per gram of dried algal powder, and the required inclusion rate is correspondingly much higher. Confirm whether an assay figure refers to the trituration or to the cobalamin itself.

Adult RDA is 2.4 micrograms per day, which bears little relation to supplement doses because of the absorption ceiling. Typical supplemental doses run 100 to 1,000 micrograms daily, and weekly 2,000 microgram protocols are used where compliance is the constraint. For people with impaired intrinsic factor the high-dose oral route relies entirely on passive diffusion at roughly 1%, so 1,000 micrograms daily is a rational target rather than an arbitrary one. Sublingual formats are widely marketed as superior; the controlled data comparing sublingual to oral at matched dose do not show a consistent advantage.

Stability determines form choice more than bioavailability does. Cyanocobalamin is the most stable crystalline form and tolerates processing, heat and storage better than methylcobalamin, which is notably light-sensitive and degrades faster in solution and in humid conditions. Methylcobalamin products need light-protective packaging and realistic shelf-life claims. Vitamin C and some trace metals accelerate cobalamin degradation, which matters in multivitamin matrices where high-dose ascorbic acid sits alongside B12. As with vitamin D3, overage is normal practice and should be agreed explicitly against the finished matrix rather than the raw material.

For analytical control, the assay method is the specification point that matters most. HPLC with UV detection distinguishes cobalamin forms and should be specified for isolated material. For algal grades, insist on a method that separates true cobalamin from inactive corrinoid analogues; a microbiological assay alone is insufficient because some analogues are active in the test organism but not in humans. Require the alga to be identified to species on the certificate. India-origin algal material ships with phytosanitary documentation on request alongside CoA and MSDS.

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Frequently Asked Questions — Vitamin B12

Related compounds: Folate / Folic Acid · Iron · Betaine · Choline · Magnesium