It's not just iron that's lacking in our diets. Magnesium is an extremely important mineral that is lacking in nearly every modern diet across the globe. it's the procressing of food that removes three crucial minerals: magnesium, potassium and iron. Back when white bread/processing was first becoming mainstream, people got all kinds of diseases because the processing removed all the B-vitamins. they actually had to pass laws to force manufacturers to re-add all the B-vitamins back into the food, after the processing. this addressed many of the most common diseases but they did'nt re-add the Magnesium and Iron, hence why everyone is deficient in Magnesium and iron. There's a pretty decent amount of research showing the connection between magnesium and diseases not typically associated with diet (and hence why this has not been addressed).
Eating a whole foods diet (non processed) can definitely address it but that's a tall order for most people.
Eating a whole foods diet (non processed) can definitely address it but that's a tall order for most people.