Hi @katya12. There are a number of members in Connect who also have been diagnosed with Macrocytic Anemia in quite a few different discussions so I’m not sure what the conditions are behind their cause for having the blood disorder.
If you’d like to read through some of the conversations type Macrocytic Anemia in the search bar and you see the threads listed.

I’m also posting a helpful link to information about Macrocytic anemia:
https://www.healthline.com/health/macrocytic-anemia
You mentioned having several tests run. Did these include a liver and/or thyroid panel? Are you on any treatments for the anemia?