Balance problem due to b12 deficiency.

Hi all, I have been experiencing off balance problem while standing and walking since 2.5 months now. Initially 1st month I was ungergoing all kind of tests like blood tests, heart tests, ultrasounds, xrays, CT scan and MRI. All the blood tests report were normal except showing b12 deficiency at 390 level, vitamin D deficiency and iron deficiency. My MRI report for Brain and Spine came normal. I also consulted an ENT and no ear infection or problem was diagnosed. Finally, after 1 month I consulted a neurologist with all the reports and the doctor said I have the balance problem due to b12 deficiency in the nerves. He says it takes for the recovery. I took Nervo injections 5 in 10 days and now weekly once along with Nervofit capsules 1 each day. Can you pls tell me how much time does it take for the recovery to happen? Why my symptoms are not improving after 1 month of medication. I feel fine while sitting and lying down. No problem while getting up from the bed too.