I have this too. What worked for me was folic acid( builds red blood cells) what we don't have enough of, and I take 1000 mcgs not mg's of b12, but first you have to have a test to see if you can absorb this orally, some people can't have to have shots. This helped me. and yes iron can be dangerous, after menopause when you don't bleed anymore too much iron can be stored up and damage organs, so don't take iron supplements if you have this. I was mis diganosed with iron defiency anemia when I was a teenager, finally when I was in my late 30's I had the doctor run a test for thallasemia, cause my relatives had it and it came back positive.