I wouldn't put much stock in the claim about b12 and/or potassium deficiencies causing AN. I have never had a deficiency of either (eat cereal with milk every day) with a balanced diet and plenty of meats, fruits, and vegetables. No vegan or vegetarian here - I eat everything and have since I was a small kid...and I still got an AN. Also, if deficiency caused it, why wouldn't both sides stop producing cells at the same rate and thus cause AN in both sides (even without NF2)? I am more likely to attribute it to other environmental factors such as cell phones, loud sounds, unrecognized prior infection in that ear, or something altogether more weird than any of those things.