As a person gets older, an autoimmune condition might develop whereby the body attacks the cells responsible for creating intrinsic factor.
If the protein isn’t created, then vitamin B12 isn’t reabsorbed into the body when it travels through the gut.
Instead, the crucial vitamin is lost via the back passage when you do a number two.
Pernicious anaemia is the name of the autoimmune condition that causes a vitamin B12 deficiency.