I was diagnosed with iron-deficiency anemia and I am Vitamin B12 deficient. I received a blood test in June, and it showed that my ferritin level was a 4! My doctor immediately put me on prescription iron (I said absolutely not to an iron infusion), but I had to stop taking the iron because it was making very sick. So now i’m taking Ferrasorb by Thorne, and I haven’t had any issues. It has vitamin C, B6, and B12, which is perfect. but I still feel tired, short of breath and fast heart rate. How long does it take for the ferritin levels to rise when taking iron, and is one pill a day enough (one pill I take has 36mg of iron)? also, has anyone experienced anxiety with low ferritin levels? I know anemic symptoms can present itself like anxiety.