Vitamin B 12, also known as cobalt amine, is the only vitamin containing metal elements. In nature, vitamin B12 is synthesized by microorganisms. Higher animals and plants cannot make vitamin B12. Vitamin B12 is the only vitamin that requires the help of an intestinal secretion (endogenous factor) to be absorbed. Some people due to gastrointestinal abnormalities, lack of this endogenous factor, even if adequate dietary sources can also suffer from malignant anemia. There is basically no vitamin B12 in vegetable foods. It stays in the gut for a long time and takes about three hours (most water-soluble vitamins take only a few seconds) to be absorbed. Vitamin B 12's main physiological function is to participate in the production of bone marrow red blood cells, prevent malignant anemia, prevent brain nerve damage. Vitamin B 12 is one of the last B vitamins to be found so far. Vitamin B12 is a polycyclic compound containing 3 valent cobalt. Four reduced pyrrole rings are linked together to form a Golin macroring (similar to porphyrin), which is the core of vitamin B12 molecule. Therefore, compounds containing this ring are referred to as Golin-like. Vitamin B12 is a light red acicular crystal which is easily soluble in water and ethanol. It is most stable under the condition of weak acid pH 4.5 and 5.0, and decomposes in strong acid (pH < 2) or alkaline solution, which can be destroyed to some extent in the event of heat. But short time high temperature disinfection loss is small, encounter bright light or ultraviolet ray is easy to be destroyed. The loss of ordinary cooking process is about 30%.

Khoom npe:	VITAMIN 12
CAS:	68-19-9
MF:	C63H88CoN14O14P
MW:	1355.37
EINECS:	200-680-0
Vitamin B12, uas hu ua VB12 rau luv luv, tseem hu ua cobalamin, thiab yog ib qho ntawm cov vitamins B, yog cov chav kawm ntawm cov organic sib xyaw ua ke muaj cov cobalt Corrin chav kawm, thiab muaj cov trivalent cobalt zoo ib yam li porphyrin Corrin lub dav hlau ntawm qhov chaw ntawm lub nplhaib .Nws yog qhov loj tshaj plaws thiab feem ntau muaj cov vitamins molecule uas tau pom. Nws tseem yog tib cov vitamin nrog hlau ion. Cov kua siv lead ua liab, nws tseem hu ua liab vitamin.Tus nroj tsuag tsis muaj VB12, thiab tsis tuaj yeem tsim VB12. Lub siab yog qhov zoo tshaj plaws ntawm VB12, tom qab ntawd los ntawm mis nyuj, nqaij, qe, ntses thiab lwm yam .VB12 yog qhov tseem ceeb coenzyme hauv kev sib txuas ntawm RNA thiab DNA. Qhov tsis muaj VB12 nyob rau hauv vivo tuaj yeem ua rau hloov pauv pathological ntawm cov hlab hlwb xws li cov leeg hlwb thiab lub paj hlwb nruab nrab.