vitamin B12 is from160-950pg/ml. Reason for such wide range is due to vitamin B12 is in our tissues plus in the blood so it is difficult to have a true reading. Suggest eating protein containing foods (60-70gms a day) at each meal which may help you with the issues you stated. Protein comes from animal and plant sources. From animal sources it comes from all meats, chicken, fish, beef, pork, etc.; and dairy products such as milk, yogurt, cheeses, pudding, and ice cream.