So vitamin D and Vitamin B12, those are known issues. Supplement if you think it's important. I personally haven't been supplementing at all and feel good. B12 growns in plant soil, so if some of the dirt is on organic plants that I eat I get it that way. We get vitamin D from the sun.
Our body makes EPA/DHA from plant based ALA.
The bio availability argument is nonsense.
RE: If you are not a vegan, you should watch this video