I posted my iron lab results recently. I am low normal in serum iron. TIBC is in the upper limit. Ferritin is low normal. Anyway, I have had textbook symptoms of anemia for a little over 2 weeks now. I honestly thought I was going to die. Had to pull over one day on the highway and call 911 because my heart was beating so fast, thought I would pass out. Have high bp, pulse rate, shortness of breath, ringing in the ears, and feel like I'm freezing all the time. The doctors say my iron is fine. It must be my heart. Well, the holter monitor I wore for 24 hrs revealed nothing abnormal. I felt like the walking dead. Anyway, I started taking an iron supplement a few days after symptoms started and after a week, felt like I was human again. The difference was amazing. It slowed my heart rate and lowered my high BP. Now, all of the sudden, I can't tolerate taking the iron supplement. It makes me feel dizzy and generally unwell. It's strange. I'm starting to get all the anemia symptoms back. I have the MTHFR gene mutation and thinking now I must have a B12 or Folate deficiency. My B12 level is normal mid-range but have read several times that it can show normal and still be deficient. Also, my doctor ran a folate test on me 5 months ago. The results said my serum folate was greater than the assay limit of 20.0 ng/ml. I'm not sure what that means but sounds like I have a high level of folate in my blood and my body isn't processing/using it. My homocysteine is 10.4 (5.0-15.0). I know the treatment for B12 or folate deficiency is to take B12 or folate supplements. In my case, it would be methyl b12/folate. Maybe that is why the iron is bothering me now. I would appreciate your thoughts/feedback.