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%.

Lebitso sehlahisoa:	VITAMIN 12
CAS:	68-19-9
MF:	C63H88CoN14O14P
MW:	1355.37
EINECS:	200-680-0
Vithamine B12, e bitsoang VB12 ka bokhutšoanyane, e tsejoang hape e le cobalamin, hape ke e 'ngoe ea livithamini tsa B, ke sehlopha sa metsoako e rarahaneng ea manyolo e nang le sehlopha sa cobalt Corrin,' me e ne e na le cobalt e ts'oanang le sefofane se tšoanang sa porphyrin Corrin bohareng ba selikalikoe. Ke molek'hule e kholo ka ho fetisisa le e rarahaneng ka ho fetisisa ea vithamine e fumanoeng. Hape ke vithamine feela e nang le ion ea tšepe. Kristale e khubelu, e boetse e bitsoa vithamine e khubelu. Semela ha se na VB12, 'me ha e khone ho hlahisa VB12. Sebete ke mohloli o motle ka ho fetisisa oa VB12, ebe o tsoa lebeseng, nama, mahe, tlhapi joalo-joalo. VB12 ke coenzyme ea bohlokoa ho kopaneng ha RNA le DNA. Ho haella ha VB12 ka vivo ho ka baka liphetoho tsa methapo tsamaisong ea methapo e kang methapo ea kutlo le tsamaiso ea methapo e bohareng.