> While for some people a plant base diet might well be good if well constructed and supplemented this is not always true on a population level.

The majority of meat eaters also have vitamin and micronutrient deficiencies, I don't think plant based diets are the issue here but general culture. Bread and salt have iodine added, but when B12 gets added to plant milks it's suddenly "supplemented". No, most diets have vitamins supplemented, and most western people are having sub optimal diets.