This is part 2 from a Conference of the P.A. Society in 2013 and as many members on this forum may have low and some very low levels of B12 it is a wake-up call. I just don't know why scientific evidence is ignored and allow people to gradually worsen or told there is nothing that can be done. There are quite a few 'parts' in this link.
The talk starts about 4 mins in.