Yes it was liver for iron. I should probably try it now again, as an adult. I might feel differently, who knows!
I would hope that if there was the possibility of supplementation in those countries, they would advocate for it and seek donations for them.
My son is a very picky eater and I basically force him to take a few supplements to try to offset what he is not eating.
Regarding Magnesium, I use a chelated version and cannot tell if it's helping or not. I do not get any loose bowels with it no matter how much I take.
I also don't get a 'calming' effect that I read about it. Just a neutral, nothing. I will keep up with it and see how it goes.
I do think the chelated versions are designed for much better absorption, though they are more expensive.