Polaris posted an interesting link the other day which is getting missed.
The article concerned was discussing stomach acid, b vitamins and thyroid.
It was also discussing how PPIs block stomach acid production.
Let's take this one step further - I don't produce stomach acid, I have low stomach acid. I suspect, going on symptoms that many out there have low stomach acid whether taking PPIs or not.
If you have low stomach acid this is what the article says:
"Thyroid function becomes flawed because of lack of vitamins B2, B3 and B6 along with the minerals iodine, zinc, selenium, magnesium, copper, molybdenum, essential fatty acids and the amino acid tyrosine. Lacking these substances thyroid hormone can not be constructed."
So without stomach acid the above minerals and vitamins cannot produce thyroid hormone.
We also know without stomach acid b12 cannot be cleaved from food.
Hence you have one direct correlation that there could be an underlying cause as to why some people have thyroid issues and a simultaneous B12 problem.
Hope this info helps some people out there.