As you read along, you'll find out that most health conditions developed by vegans are related to vitamin B12 deficiency. Without the familiar sources of vitamin B12, certain bodily functions can be disrupted, leading to anemia, gastritis, stroke, Crohn's disease, and Celiac disease.

Yet one thing all vegans have in common is a plant-based diet avoiding all animal foods such as meat (including fish, shellfish and insects), dairy, eggs and honey - as well as avoiding animal-derived materials, products tested on animals and places that use animals for entertainment.