I would not worry about it too much if this was you only abnormal test and everything checks out fine. Percentage-wise, you are not that far out of range.
But, if you did not have a full screening panel done, it might be a good idea. High B12 levels can be associated with some blood diseases or liver disease. It could also be just a problem with the sample. So, a repeat B12 is in order at the least, and liver enzymes, CBC, etc, if not already done.
Jan