What about iodized salt? Iodine (a mineral) is added to salt to prevent thyroid issues and goiters because many parts of the world don’t have iodine freely available in foods/soil.
What about vitamin d fortified milk? It’s added, along with calcium, to milk to prevent rickets. And it does prevent rickets.
While neither of these examples are taken in the traditional sense of a vitamin or mineral (tablet, capsule, liquid form), they’re still “supplements” in the sense that they’re nutrients added to foods which don’t contain the vitamin or mineral in high amounts naturally. But both salt and milk are consumed by many, so it’s a broad-based way to distribute these nutrients to those who may not get them otherwise.
Not being snarky here at all, by the way....But, just to clarify, is your argument that the standard vitamin or mineral supplement we buy in a bottle is worthless and have no impact on health? Or is it that all supplements, regardless of how we get them, outside of the natural sources found in foods and soil (like B12 and iodine), are worthless and have no impact on health?