I have b12 deficiency for 7 years .this october it is diagnosed. The main symptoms are brainfog and tiredness. I have been using tabs 1500 mcg and injections for b12 750 mcg every week and 5 loading injections. Its been 15 days. Tiredness is improved .will someone suggest how long it takes brainfog to reverse. I have seen lift in mood and attentive to others after shots. As the deficiency is undiagnosed for 7 years the brainfog will remain permanent or it will go away with time. There are no nerve damage except pulling sensation in legs and hands. Sometimes tingling and numbness. Can anybody suggest how long does it take brainfog to get treated as I wanted to grt a job and any remedies are welcome.