While you're correct that some animal-based foods contain B12 and vitamin D naturally, many people who eat meat and fish need to supplement it because it's just not enough. For vitamin D, this is especially true for people living in higher latitudes because there's not enough sun light.
I think you're not clear what the definition of "essential" in biology is. Essential means that it cannot be synthesized by the organism, but needs to be taken in externally. The studies you have linked do not talk about synthesis in the human body. A quick lookup on Wikepedia explains clearly that all other mentioned items are synthesized by humans.
I think you're not clear what the definition of "essential" in biology is. Essential means that it cannot be synthesized by the organism, but needs to be taken in externally. The studies you have linked do not talk about synthesis in the human body. A quick lookup on Wikepedia explains clearly that all other mentioned items are synthesized by humans.