I originally entered this thread trying to see if others possibly connected their sudden iron deficiency to the CoViD vaccinations. There is no medical support - at this time - for such an anomaly. A gastrointestinal workup is a wise next step for you, also, perhaps a bone marrow biopsy if your hematologist thinks so.

I also recently experienced a second dive in my iron readings, not as severe as the first; by the time I got to my hematologist the readings had mostly spontaneously corrected; I am taking a second series of Venofer iron injections notwithstanding at the doctor's recommendation. A GI series showed no significant bleeding problem for me. Unhappily, my hematologist thinks that I have a deteriorating kidney problem but my PCP does not; right now I tend to agree with my PCP. I declined for now a series of Procrit {Retacrit} injections. The hemoglobin {chronically marginally low} does not really support that therapeutic route so far, plus the iron must be normalized at the same time for Procrit {Retacrit} to work as I understand that.