Do you know why your B12 was low? Understanding that may provide insight to your overall situation. If you are low on B12, there's a chance other nutrients are low or low normal. They normally don't test everything and blood serum is not always the most accurate method of testing. B12 is important to restore but you should also make sure you're getting the other B vitamins. They also support nerve health. A good B Complex that has the bio-available forms of B1, B6 and folate would be my choice. I echo what Lara stated about the type of B12. The methyl form is more bio-available. That's important if your body cannot convert the cyano version into a usable form.

Too little copper and too much zinc can effect nerves. Iron,copper and zinc need to be in balance.

There are reasons for low B12....being a vegan, celiac disease, gluten intolerance, malabsorption issues, and other digestive issues.

Nerves do heal slowly. Sometimes, you progress then plataeu for a while. And at times, it may feel worse for a bit as the nerves are healing.