Beer and Wine Isinglass, a gelatin-based substance derived from fish, is used as a clarifying agent in some beer and wine. Other non-vegan ingredients sometimes used are casein (from milk) and egg whites.

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.

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.