Fourteen years ago, there were my own money troubles, so that I was needing to get food where there was help for that, this made a difficulty in going vegan when I might have otherwise. Going vegan itself right after that difficulty was not hard, I can give tips for that.
Studies are actually limited on this. Actual deficiency seems to only occur when intake is less than 50mg/day, which is why vegans generally don’t all drop dead from fatty liver disease even though their daily intake is less than the adequate intake recommendation.
But, again, studies are limited. Society doesn’t really care if vegans kill themselves so no one bothers to study this kind of stuff. I supplement with 250mg/day, because I only really get around 200mg/day from my normal diet and I don’t feel like eating several cups of soybeans lol