I just had my 4th Covid shot (2nd booster) from Moderna on Friday 09/16. On Monday 09/19 I had various labs done at my rheumatologist and my serum iron came back very low (a 26). My primary care doctor followed this up with another iron serum test on 09/22 to make sure that the lab hadn't made a mistake (I just had 2 iron infusions on in July the 2nd being 07/27- less than 2 months ago) I do have a history of iron deficiency anemia, however I ususally go 18 months in between infusions before my iron levels start to drop again. This time it dropped in less than 2 months and the only difference is the 4th Moderna shot. The CDC contacted me last night and helped me in filling out a VAERS report. I have a pending appointment with my hematologist, 2 more infusions and more blood work pending. I, too, am curious to see if there is any connection. I wouldn't have changed getting the booster, as I am immunocompromised, but had it not been for the follow up lab work we wouldn't have caught the low iron serum until later (also just a side note that my hemoglobin and RDW levels were normal- generally these are the first numbers to indicate my iron deficit).