Bacterial overgrowth in your small intestine can give you high levels of B12!
Bacterial overgrowths that should not be in your small intestine can produce B12. You may know a lot of people with autoimmune conditions have low iron or low B12. What I’ve seen is people can also have high levels of B12. The reason for that is - the specific bacterial overgrowths that they have inside their small intestines produce Vitamin B12, rather than eat it!
So, if you’re suffering from an autoimmune & digestive issue and you have high or low B12, it can show an infection or overgrowth in your small intestines. If you got high B12, it can also be from high meat and dairy diet. If you got low B12, it can be from more of a vegan or vegetarian diet.
But, if you’re not supplementing with VItamin B12 and you’re not eating too much B12, and you still got high and showing other symptoms of digestive and autoimmune conditions, it’s likely you’ve got bacterial overgrowth in your small intestine.