Taking stock. The account presented above shows that vegan diets can fulfil all the nutritional requirements that are needed to support good health. Nutrients that present particular concerns are vitamin B12 and omega-3 fatty acids as few vegan foods that are currently used for human consumption contain these.

At a minimum, people who call themselves vegans avoid products including meat, fish, dairy, honey, gelatin, leather, wool, suede, fur, feathers, and silk—but being vegan means more than simply changing one's dietary habits. It's also a lifestyle.

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.