About
Cyanocobalamin is the most common synthetic, shelf-stable form of vitamin B12 — an essential water-soluble cobalamin — used to fortify foods and dietary supplements. It is required for DNA synthesis, red blood cell maturation, and normal neurological function; the body converts it to its active coenzyme forms methylcobalamin and adenosylcobalamin.
Safety summary
Cyanocobalamin has an excellent safety profile at nutritional and supplemental doses; no tolerable upper intake level has been established by WHO, EFSA, or the US Institute of Medicine due to its low toxicity and efficient renal clearance of excess. Individuals with Leber's hereditary optic neuropathy (LHON) should avoid cyanocobalamin because its cyanide ligand can exacerbate optic nerve damage — hydroxocobalamin is the preferred alternative. Very high pharmacological doses (>1 mg/day) may warrant caution in those with severe renal impairment, where accumulation and elevated cyanide load are possible.
Regulatory landscape
| Jurisdiction | Status | Note |
|---|---|---|
| FSANZ (Food Standards Australia New Zealand) (Australia) | Approved | Cyanocobalamin is a permitted form of vitamin B12 for addition to foods under Schedule 1 of the Australia New Zealand Food Standards Code. Conditions of use vary by food category.source |
| EFSA (European Food Safety Authority) (European Union) | Approved | Cyanocobalamin is a permitted vitamin form in food supplements for human consumption under Directive 2002/46/EC (Annex I and II). Also authorised as a nutritional feed additive for all animal species without time limit under EU Register of Feed Additives pursuant to Regulation (EC) No 1831/2003. No E number is assigned because the substance is regulated as a nutritive additive, not a functional food additive.source |
| FSSAI (Food Safety and Standards Authority of India) (India) | Approved | Permitted in food fortification and nutraceuticals/dietary supplements under the Food Safety and Standards (Fortification of Foods) Regulations, 2018 and FSS (Health Supplements, Nutraceuticals, etc.) Regulations. Listed as an approved vitamin for addition to staple foods and supplements.source |
| FDA (Food and Drug Administration) (United States) | Approved | Affirmed GRAS as a direct human food ingredient (nutrient supplement) under 21 CFR 184.1945; permitted at GMP levels with no specified maximum. Also regulated as a dietary supplement ingredient and used in food fortification per FDA fortification policy (21 CFR 104.20). |
Who should approach with care
Research citations
- 1FDA. Code of Federal Regulations Title 21, Part 184.1945 — Vitamin B12 (Cyanocobalamin). accessdata.fda.gov
- 2other. ECHA Substance Information — Cyanocobalamin (EC 200-680-0, CAS 68-19-9). echa.europa.eu
- 3EFSA. Safety and efficacy of a feed additive consisting of vitamin B12 (cyanocobalamin) produced by fermentation with Ensifer adhaerens CGMCC 21299 for all animal species (NHU Europe GmbH), 2024. efsa.europa.eu
- 4EFSA. Scientific Opinion on safety and efficacy of vitamin B12 (cyanocobalamin) produced by Ensifer adhaerens when used as a feed additive for all animal species, 2015. efsa.europa.eu
- 5WHO. Vitamin and Mineral Requirements in Human Nutrition, 2nd Edition — WHO/FAO, 2004. who.int