question: Hello I have secondary progressive MS. I have been told to take Vitamin B12 pills to help with my memory and tiredness. I am not sure how many B12 pills to take. I take one 1000mg pill a day. I am also on Citalopram 10mg and Baclofen 10mg. What dose of Vitamin B12 is it safe to take. Brian Measer. I am 64 years old.