How much in one pill? How much is enough?
I knew a woman that got B12 shots long long ago.
There are a variety of issues with B12. Many depend on your genetic engineering.
You have to do trial and error.
In the US they use the B12 shot that has cyanide in it. What I needed was the version used in Europe that has been broken down somewhat
https://www.mcpiqojournal.org/article/S2542-4548(19)30033-5/fulltext
If you have had a path review done on a CBC you can look for signs of a B12 issues. Hypersegmented neutrophils. But don’t expect your primary care physician to know jack about any of it