From personal experience and blood tests, a balanced vegan diet is just fine, except I just found out that I was living for years with B12 deficiency ( sadly not deemed worth checking in normal blood tests by my doc)

That oversight resulted in day to day life disorder for me that only ended when I supplemented a strict plant based diet with local goat cheese and eggs and recently the odd can of sardines.

That seems to keep me very happy, and positive and realistically true to my principles, full of B12.