I mean, in regards to iron specifically, I get bloodwork done in my yearly checkup and it will tell me my iron levels.

Historically mine have always been low but in September of 2023 I started a diet and started taking iron supplements, and when I got my bloodwork I was in the happy "green" range.

ETA:

I should point out that I'm a pretty tall dude (~6'5"), which might make it easier for me to avoid getting too much iron, but if I were getting too much iron I assume it would probably show up in my blood tests?