What would be the chemical reaction of Vitamin b12 with an acid?

Question

I am trying to do a chemistry project on vitamin b-12 and it asks how B-12 would react with acids and bases. I have looked everywhere online and I cant find a straightforward question. 

Answer 1

The structure of B12 is very complex, probably the most complex of all vitamins.  As is true with other vitamins, it contains and amine group (-NH) and several amide groups (-CONH2).  Acid will react with the amine to produce the protonated -NH3^+ and the amides will be hydrolyzed to -COOH + NH4+ and the corresponding cation (Cl- for HCl, for example).

What other reactions might occur (such as protonation of the phosphate group) is difficult to predict.