B vitamins help support adrenal function, help calm and maintain a healthy nervous system, and are all necessary for key metabolic processes. Vitamin B12, also known as cyanocobalamin, is necessary for DNA synthesis and affects the development of red blood cells, normal myelination (covering) of nerve cells, and the production of neurotransmitters. Deficiencies of B12 can lead to memory loss, confusion, fatigue, and even dementia.
Animal-derived foods, including dairy, eggs, meat, fish and poultry are the only food sources of B12, so this important vitamin is often deficient in vegan diets. Good sources are clams, herring, cooked oysters and wild Alaskan salmon. To help meet daily needs, Dr. Weil recommends a B-complex supplement that contains a full spectrum of B vitamins, including thiamine, B12, riboflavin and niacin.