I've been trying to post the link but, for some reason cannot - only available for 24 hours but very interesting. They mention the importance of B12 being absorbed from acid in the gut.
'Tonight begins the second episode of Betrayal: The Autoimmune Disease Solution They're Not Telling You.
Episode 2: The Leaky Gut Problem, Detection And Diagnosis, Rheumatoid Arthritis, Case Studies Of Gut Disease and Reversal.
The truth about the leaky gut and rheumatoid arthritis connection
The issue with vitamin deficiency and poor absorption
The vitamin d deficiency connection to leaky gut
The importance of a healthy gut
What intestinal permeability is, and why you need to know about it'