There has been a growth in veganism in the past decade. Yet, there are people who switch back to non-vegan diet just because they feel that they are facing deficiencies in their body due to vegan diet.
This is the basic debate with which people start with while answering why are they not going vegan. There are number of vegans around the world who feel more healthier after shifting from meat-based diet to vegan one. This is because they follow the correct diets and patterns.
If someone debates on the same topic, you can ask them to refer this article (https://www.vegansfirst.com/vegans-vitamin-b12-without-supplements/) which clearly states how well vegans can maintain vitamin B12 in their diet and won’t need to eat innocent animals for it.
Let me know all of your thoughts on it.