Did they accurately measure them in 1940? I would also think trace minerals vary at least a little based on geographical location. Anyway here is a journal art

Did they accurately measure them in 1940? I would also think trace minerals vary at least a little based on geographical location. Anyway here is a journal article by a Canadian govt scientist that refutes that minerals in food/soil is depleted: https://www.sciencedirect.com/science/article/pii/S0889157516302113 https://www.sciencedirect.com/science/article/pii/S088915751...