RESULT MAY VARY FROM PERSON TO PERSON   Vitamin B-12 is necessary to maintain healthy cognitive function, healthy nerve cells, and energy production. It is also essential for DNA production and for maintaining the normal production of healthy red blood cells. B-12 is normally found in meat, seafood, eggs and dairy. Older people tend to have less stomach acid, which may result in less absorption of B-12 from food. The Food and Nutrition Board of the Institute of Medicine recommends everyone over the…