Here is my (ongoing) thread to detail my B12 journey. Here goes!
2-3 years before diagnosis I began having the following symptoms. Numbness in toes which slowly spread to feet then ankles, then calves. A slow deterioration of muscle tone all over. Periods of intermittent dizziness/vertigo and fatigue. A worsening of lifelong digestive symptoms which include inflammation and constipation, decreased gut motility.
A year before diagnosis I suddenly felt my spine growing cold when I was waking in early mornings. I thought it might be my old mattress so I bought a new one, but that didn't help. My fatigue was also getting worse.
A few months before my diagnosis my symptoms increased. It seemed like everything was going wrong all at once. My foot/leg neuropathy worsened to include weakness in upper legs. My balance worsened, especially upon waking up. I also began to feel occasional nausea and shortness of breath. I was diagnosed with cataracts, borderline macular degeneration and glaucoma.
A week before diagnosis the bottom of my feet started to feel burning sensations and I began to go into unexpected rages without any trigger, no good reason. I also began having dark thoughts that would come on with intensity. I was beginning to forget words. I began to have leg cramps and not just spinal cold sensitivity. I felt waves of cool energy zipping up the back of my head.
My (American) doctor who I had seen for 10+ years thought I had shedding from covid patients, a kind of long covid. I doubted this, so In a panic I found a new (Mexican) doctor.
I spent my first session with him detailing all my various ailments, in between burst of crying.
On my second visit with my new Mexican doctor he said, I have something to help you. I didn't think anything could help but was willing to try. He gave me a B12 IV. About halfway through the IV my dark mood lifted and then I began to feel a little more capable of standing, walking and balancing.
I then proceeded to receive B12/B6/B1 injections at intervals of 8 - 10 days. I could tell with each shot my neuropathy was getting better. I began a journal to try to discover how many days would be best to wait before a new shot.
I am now on my 38th shot. I slowly reduced the intervals and find that every five days is best for me since on day 6 my neuropathy and bad mood would start up. The 5 day interval is working well for me. I am thrilled that I was finally diagnosed correctly.
I have a lot more to tell you all, and will do so in subsequent posts. I found this forum around my 4th shot and it has helped a lot.
God Bless you all.
I have taken methyl folate for years along with other supplements for the MTHFR mutation. I was very surprised when I was B12 deficient. I am sure I will need injections for the rest of my life and I am ok with it. Two of my Mexican neighbors are proficient in giving the injections so I just run to them and it gives me a chance to socialize too. My new doctor is a miracle worker and best of all only costs $35 usd for a visit. Five B12/B1/B6 injections cost about $7 usd and I buy them at local pharmacies. What I would like to take is just B12 without the B1 and B6 but that is not available here. I am happy to answer any other questions. 
