Hydroxocobalamin

Hydroxocobalamin suppliers and sourcing guide

Hydroxocobalamin is a form of vitamin B12 in which a hydroxyl group sits on the cobalt atom where cyanocobalamin carries a cyanide group. Like the other cobalamins it is made by bacterial fermentation, then extracted, purified and crystallized, and it is usually sold as the acetate or hydrochloride salt. Because tablet and capsule doses are measured in micrograms, most brands buy it as a dilute trituration on a carrier rather than as the dark red crystalline powder.

See suppliers What to ask for on the COA

Category: Vitamins and minerals
Also known as: Hydroxocobalamin acetate · Hydroxocobalamin hydrochloride · Vitamin B12a · OH-cobalamin
Facts checked: November 2026

Forms and grades of hydroxocobalamin

Suppliers sell different products under the same name. Specify the one you need.

Hydroxocobalamin acetate
Dark red crystalline powder, the salt most often offered for food and supplement use; the COA should say which salt and whether results are on the dried basis.
Hydroxocobalamin hydrochloride
An alternative salt with a different molecular weight, so the vitamin B12 content per gram differs from the acetate.
Triturations
Hydroxocobalamin diluted to a stated strength (for example 1% or 0.1%) on dicalcium phosphate, mannitol, maltodextrin or microcrystalline cellulose so micrograms can be dosed evenly.
Spray-dried and coated grades
Dilutions spray-dried or coated for dispersion in drink mixes, gummies and premixes, with the carrier named on the specification.

What to check on the COA

Compare each result with your own specification when the lot arrives.

Identity: UV-visible absorption spectrum and HPLC retention time against a hydroxocobalamin reference standard, which separates it from cyanocobalamin and methylcobalamin.
Assay (HPLC): Hydroxocobalamin content by HPLC, on the dried basis for crystalline material and as a percentage of label strength for triturations.
Related cobalamins: Cyanocobalamin and other cobalamins and degradation products reported by HPLC as impurities.
Loss on drying: Water content of the crystalline salt, which is hygroscopic and can hold a variable amount of water.
Content uniformity: For triturations, assay of several samples from the lot to show the low-percentage blend is even.
Heavy metals and microbiology: Lead, arsenic, cadmium and mercury by ICP-MS, plus total plate count, yeast and mold for diluted grades.

Storage, lots and expiry

Storage and shelf life

Hydroxocobalamin breaks down in light, so keep it in tightly closed, light-resistant containers, cool and dry, and reseal opened packs promptly. Triturations should also be kept away from heat and humidity because the carrier can take up moisture. Shelf life comes from the supplier's stability data and specification, and older stock is usually retested by HPLC before use.

Lots and expiry dates

Record the actual assay and the carrier for each lot, since trituration strength sets the amount added to a batch and small assay shifts matter at microgram doses. Rotate stock first-expired, first-out and recheck assay on any lot exposed to light.

Regulatory status

Facts from regulators and standards bodies, each linked to its source.

Health Canada's Multi-Vitamin/Mineral Supplements monograph for natural health products lists hydroxocobalamin and hydroxocobalamin acetate among the source ingredients for vitamin B12 (Table 1).
Source: webprod.hc-sc.gc.ca (opens in a new tab)
21 CFR 101.9(c)(8)(iv) sets the Reference Daily Intake for vitamin B12 at 2.4 mcg for adults and children 4 years and older.
Source: ecfr.gov (opens in a new tab)

This is general information, not regulatory advice. Status differs by country and by how the ingredient is used, so check the rules for your product and market.

Hydroxocobalamin suppliers

Manufacturers and distributors whose own websites say they sell it.

We are checking hydroxocobalamin suppliers now

Every listing is checked against the supplier’s own website before it goes live, so this list fills in over the coming weeks. The specs and COA checklist above are ready today.

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Frequently asked questions

What forms of hydroxocobalamin can brands buy?

Common forms include hydroxocobalamin acetate, hydroxocobalamin hydrochloride, triturations and spray-dried and coated grades. Ask each supplier for the specification sheet of the exact grade they quote.

What should the COA for hydroxocobalamin include?

Expect identity, assay (HPLC), related cobalamins, loss on drying, content uniformity and heavy metals and microbiology, each with its method, specification and result for that lot.

How should hydroxocobalamin be stored?

What is the regulatory status of hydroxocobalamin?

Health Canada's Multi-Vitamin/Mineral Supplements monograph for natural health products lists hydroxocobalamin and hydroxocobalamin acetate among the source ingredients for vitamin B12 (Table 1). 21 CFR 101.9(c)(8)(iv) sets the Reference Daily Intake for vitamin B12 at 2.4 mcg for adults and children 4 years and older.

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