Dear Doctor, I had GERD for which I'm taking treatment. At the same time my vitamin B12 was 92. So doctor suggested for b13 injection , 1st month weekly once, and from 2nd month every 30 days for 6 months. I use to feel weakness and dezzyness before the start of treatment after 1 month i was feeling better now the monthly injection had started and i have taken only the 1st monthly dose...now some times feels like dezzyness and weakness. How long does it take to correct the deficiency ? Thank u.