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%.

Oloa igoa:	VITAMIN 12
CAS:	68-19-9
MF:	C63H88CoN14O14P
MW:	1355.37
EINECS:	200-680-0
Vitamini B12, lea e taʻua VB12 mo puʻupuʻu, taʻua foi o le cobalamin, ma o se tasi o le B vaitamini, o se vasega o laʻau totoga faigata aofia ai cobalt vasega Corrin, ma o loʻo i ai trivalent cobalt i tutusa porphyrin Corrin vaʻalele i le ogatotonu o le mama .O le sili lapoʻa ma sili ona faigata vaʻavaʻai mole ua maua. E naʻo le pau foʻi le vaitamini e iai uʻamea. O le tioata e mumu, e taʻua foi o le mumu vitamini. O le laʻau e le aofia ai VB12, ma e le mafai ona gaosia VB12. O le ate o le sili sili punaoa o VB12, ma mai susu, aano o manu, fuamoa, iʻa ma isi. VB12 o se taua coenzyme i le tuʻufaʻatasiga o RNA ma DNA. O le le lava o le VB12 i le ola e mafai ona mafua ai pathological suiga i le neula pei o le peripheral neula ma totonugalemu sisiva.