Don't know if this video about B12 deficiency has been posted before but it might be easier to listen than to read the many papers on this.
news.bbc.co.uk/democracyliv...
It is dated March 2012 and things have moved on but useful all the same as so many thyroid people seem to suffer from B12 deficiency or have trouble getting GPs to acknowledge it let alone treat this.
If only we could petition in the same way about the poor thyroid diagnostic tests and poor treatment......