Trace Nutrients
Some trace nutrients, such as Vitamin B12 and essential fatty acids (EFA's) like omega-3 and omega-6 fatty acids, are rare in the plant kingdom. Vitamin B12 is present in nutritional yeast, and EFA's occur in nuts and plant oils, such as flax oil or primrose oil. They can also be obtained from supplements, and they are added to many foods, like breakfast cereals and soymilk.