[Maru]

I distinctly remember my nurse assistant some time back during my physical asking if I were on a special diet (vegetarian/vegan) and when I said "No", she said "Good". In other words, they shouldn't expect too many problems when they run my bloodwork... I think I had asked about it, but I don't remember exactly what she said, but I think that was gist of it.

It might be because some people go really overboard and go strict with their diet and stick to certain staple comfort foods that don't fill the gap, especially if they struggle with cravings.

I've sometimes struggled with Iron because 1) female and 2) Not being a heavy eater to begin with. I do eat meat though.

If that person is a heavy caffeine person or drink/eats lots of beverages and other processed crap that cause their body to dump nutrients, they can have an issue also. So there's lots of reasons to run into deficiencies. It's hard to blame it on one single thing.