Vitamin B-12 is a vitamin that is only found in animal products. Vitamin B-12 plays a key role in the normal functioning of the brain and nervous system and for the formation of the blood. The Vegan Society, the Vegetarian Resource Group, and the Physicians Committee for Responsible Medicine, among others, recommend that vegans either consistently eat foods fortified with B. Fortified breakfast cereals are a particularly valuable source of vitamin B for vegetarians and vegans.
Vitamin B-12 deficiencies:
Fatigue, Tingling in the Hands, Sleep Disorders, Irrational Anger
Depression, Obsessive Disorder, Manic Depression, Dementia/ Alzheimer’s
Multiple sclerosis, Anemia, Cancer Heart Disease
SOURCE: Integrative Nutrition and World Wide Web