Unsure if this is OP’s angle, but I have pretty chronically bad anemia/ferritin levels. In my layman’s research, I found that both dairy (calcium) and tea (oxalates) inhibit the body’s ability to absorb iron when consumed alongside one-another. My list also included peas, coffee, eggs, and just about every other damn thing I like to eat, so that was a fun discovery. 😅 Link to kickstart research for anyone curious.