A human brain is a chemical processor whose first job is to find and ingest the right stuff to function normally. Eating behaviors are generated by the oldest regions in the brain and are closely linked to the basic patterns of life, which are hunger, thirst, sexual arousal, flight, fight, fear, and anger. Since the brain is the organ of the mind, molecular influences on the brain are manifest as mental influences.

Nutrition influences brain function in a variety of ways. The brain disturbances of an alcoholic, unstable diabetic, pellagra victim, or elderly patient with vitamin B₁₂  and/or   folic acid deficiency are all recognized examples of nutritional mental illnesses. Vitamin deficiency is always a concern with brain dysfunction, and the risk of deficiency increases as mental disorder increases. B-vitamins play a critical role in brain function.

Vitamin B ₁₂ deficiency is a notable cause of numbness, tingling, incoordination, and impaired cognitive function. Niacin deficiency presents as dementia, dermatitis, and diarrhea. Thiamine deficiency causes cognitive dysfunction and is fully expressed in malnourished alcoholics as Wernicke's psychosis. Vitamin-mineral supplementation is always a desirable component of nutritional therapy, although high doses of individual nutrients are only desirable in acute deficiency states.

Page 2 of the Mind Brain Tutorial...  
 

Human Brain in Health and Disease