On 03/02/2021 11:37, Jim Jackson wrote:

A lack of B12 can result of analytical thought.
^

I assume there is a "in lack" lacking there! Or something similar.

Apologies, yes you are correct.

As a sufferer of Pernicious Anaemia, I know lack of B12 can affect nerve
function, hence I suppose brain function. But my (slight) nerve symptoms
were in my arms and legs. I'd always put down the slight depression
before disgnosis as related to exhaustion due to the anaemia.

Was this down to a lack of one of the 3 enzymes required to absorb B12?
Normally what would be called Intrinsic Factor.

I hope you are now feeling a great deal better.