If minerals have been depleted from our soil, where did they go? Is that just a marketing strategy to sell vitamins and minerals?

They have been depleted because we use the same soil over and over again. In the old days...100 years ago, the farmers had so much land, that they wouldn't farm the same land for 4-5 years. This would allow the soil to recover, and absorb minerals from the rain, fallen leaves and dead insects (which are rich in minerals too.)Many of today's farmers are greedy, plus they have to pay help on the farm because families don't have 7 kids to work for free. Farming is a hard way to make a decent living. Many farmers are forced to use ALL of their land at once. Hope this helps explain.