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%.

Produktuaren izena:	12. BITAMINA
CAS:	68-19-9
MF:	C63H88CoN14O14P
MW:	1355,37
EINECS:	200-680-0
B12 bitamina, laburki VB12 deitzen dena, kobalamina izenarekin ere ezagutzen dena, eta B bitaminetako bat da, kobalto Corrin klasea duten konposatu organiko konplexuen klasea da, eta eraztunaren erdialdean Corrin plano porfirina antzeko kobalto trivalentea dauka. .Aurkitu den bitamina molekula handiena eta konplexuena da. Ioi metalikoa duen bitamina bakarra ere bada. Kristala gorria da, bitamina gorria ere esaten zaio.Landareak ez du VB12, eta ezin du VB12 ekoiztu. Gibela da VB12 iturri onena, gero esnea, haragia, arrautzak, arraina eta abarrekoak. VB12 funtsezko koenzima da RNA eta DNA sintesian. VB12 in vivo ez izateak aldaketa patologikoak sor ditzake nerbio sisteman, nerbio periferikoan eta nerbio sistema zentralean, esaterako.