I had very low iron and hemoglobin. I had the last Moderna booster in December and began to feel tired and out of breath in January. I saw a cardiologist in Feb with no significant finds related to the shortness of breath. My GP ran new blood work and found the issues. I have had 2 iron infusions, iron pills , and endoscopy and seen a hematologist. No one seems to know what caused it. I just started investigating to see if the vaccine could possibly have caused it.