Well, you certainly seem to know a lot of vegans on a very personal level, and an awful lot about their various medical conditions. And it makes them liberal as well. LOL! Do they have any actually diagnosed medical issues or is this your expert medical opinion?
Too many sadly. I can add they are also as a group very demanding that omnivores are killing the planet. They expect to be catered to when they come to visit you for a few days, i.e., make sure you have vegan approved snacks and that you cook their food for them. However, when you go to their homes do not expect the same consideration in return. They expect you to eat what they eat, period. And yes most of the females in their forties are already staring to show signs of osteoporosis.
No medical degree just years of empirical data gathered through observation and having to deal with them. I’m sure there are vegans who do not match these personal observations, but I don’t know any of them.