Vegans can actually inadvertently stumble into this: a lot of tofu scramble recipes call for 2tbsp of nutritional yeast, and the bottles sold by e.g Braggs in America are heavily fortified.
Then it’s also used in cheese sauces, etc - to the point where it’s somewhat of a meme to just add it whenever you want umami. Then many vegans already take a B multi to handle B12.
Point of all this being that this particular diet can lead to overdosing on B6 without realizing it. Once I got myself a non fortified Nutritional Yeast for baking/cooking, I noticed changes in myself for the better.