. "# Wickramasinghe SN: Morphology, biology and biochemistry of cobalamin- and folate-deficient bone marrow cells. Baillieres Clin Haematol. 1995 Sep;8(3):441-59. \"Pubmed\":http://www.ncbi.nlm.nih.gov/pubmed/8534956 # Sharabi A, Cohen E, Sulkes J, Garty M: Replacement therapy for vitamin B12 deficiency: comparison between the sublingual and oral route. Br J Clin Pharmacol. 2003 Dec;56(6):635-8. \"Pubmed\":http://www.ncbi.nlm.nih.gov/pubmed/14616423 # Hall AH, Rumack BH: Hydroxycobalamin/sodium thiosulfate as a cyanide antidote. J Emerg Med. 1987;5(2):115-21. \"Pubmed\":http://www.ncbi.nlm.nih.gov/pubmed/3295013 # Andres E, Noel E, Goichot B: Metformin-associated vitamin B12 deficiency. Arch Intern Med. 2002 Oct 28;162(19):2251-2. \"Pubmed\":http://www.ncbi.nlm.nih.gov/pubmed/12390080 # Gilligan MA: Metformin and vitamin B12 deficiency. Arch Intern Med. 2002 Feb 25;162(4):484-5. \"Pubmed\":http://www.ncbi.nlm.nih.gov/pubmed/11863489"@en . . . . "Vitamin B12 is used in the body in two forms: Methylcobalamin and 5-deoxyadenosyl cobalamin. The enzyme methionine synthase needs methylcobalamin as a cofactor. This enzyme is involved in the conversion of the amino acid homocysteine into methionine. Methionine in turn is required for DNA methylation. 5-Deoxyadenosyl cobalamin is a cofactor needed by the enzyme that converts L-methylmalonyl-CoA to succinyl-CoA. This conversion is an important step in the extraction of energy from proteins and fats. Furthermore, succinyl CoA is necessary for the production of hemoglobin, the substances that carries oxygen in red blood cells."@en . . . . . . . . "Very high (to specific plasma proteins called transcobalamins); binding of hydroxocobalamin is slightly higher than cyanocobalamin."@en . . . . . . . . . . . . . . . . . . . . . . . . . . "approved"@en . . . . "For treatment of pernicious anemia (due to lack of or inhibition of intrinsic factor) and for prevention and treatment of vitamin B 12 deficiency."@en . . . "Cyanocobalamin (commonly known as Vitamin B12) is the most chemically complex of all the vitamins. Cyanocobalamin's structure is based on a corrin ring, which, although similar to the porphyrin ring found in heme, chlorophyll, and cytochrome, has two of the pyrrole rings directly bonded. The central metal ion is Co (cobalt). Cyanocobalamin cannot be made by plants or by animals, as the only type of organisms that have the enzymes required for the synthesis of cyanocobalamin are bacteria and archaea. Higher plants do not concentrate cyanocobalamin from the soil and so are a poor source of the substance as compared with animal tissues. Cyanocobalamin is naturally found in foods including meat (especially liver and shellfish), eggs, and milk products. [HMDB]"@en . "nutraceutical"@en . . "Cyanocobalamin"@en . . "Anaphylactic reaction (skin rash, itching, wheezing)-after parenteral administration. ORL-MUS LD₅₀ > 8000 mg/kg"@en . . "68-19-9"@en . . . . . . . . . . . . . . . . . . . "Robert H. Allen, \"Preparation of samples for vitamin B12 and/or folate assay and assay.\" U.S. Patent US4451571, issued October, 1982."@en . . . . . . . . . . . . . . . " "@en . . . . . . . . . . . . . . . . . . . "Humans and other mammals"@en . . . . . . . . . . . . . . . . . . "Cyanocob(III)alamin"@en . . . . . . . . . . . . . "Readily absorbed in the lower half of the ileum."@en . . . "Vitamin B12 complex"@en . . . . . . . . . . . "Approximately 6 days (400 days in the liver)."@en . . . "Vitamin B12"@en . . .