Anemia

Ferrous Sulfate. Take 325mg twice a day. Well, that's at least what I'm doing. I have low-iron anemia and that's what my endocrinologist put me on. She said it takes about 6 months for iron levels to fully recover.

Then again, things may be different in your case, especially depending on your bloodwork. I recommend you get an endocrinologist if you haven't already.

This is a serious question…are you female?
Because iron deficiency anemia in a male is colon cancer until proven otherwise.
There are different types of anemia that would not be related to colon cancer, but those would not need iron supplementation.

I found it interesting that runners can suffer from iron deficiency due to crushing red blood cells in their feet.

Depends on the type of anemia.
If folic acid deficiency, b12 or iron will not help.
If b12 deficiency, folic acid or iron will not help. In fact, additional folic acid for a b12 anemia can mask a b12 anemia. That’s why folic acid 1 mg is prescription but lesser strengths are otc.
If iron deficiency, then b12 or folic acid will not help.