Unfortunately, due to the highly restrictive nature of the diet, vegans are at risk of being deficient in certain nutrients such as calcium and vitamin B12 usually found in dairy and meat respectively.

Vegetarians don't eat the flesh of animals, such as meat, poultry, and fish, but they often eat dairy and eggs. Vegans don't eat any animal foods. This even includes foods that are produced by animals, such as honey.

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.

However, veganism is a stricter form of vegetarianism that prohibits the consumption or use of any products that come from animals, including dairy, eggs, honey, leather goods, wool, and silk. Vegetarians may eat dairy products, eggs, honey, and other byproducts that do not involve the slaughter of animals.