Vitamin B12 is best known for its mental energy producing effects, but it does much more. It is essential for cell growth & replication within the central nervous system. As we age, our digestive systems are less efficient at pulling B12 out of the foods we eat. This leaves elderly populations with significantly lower blood levels of B12 than younger populations. Vitamin B12 supplementation can both increase mental energy levels and protect against age-related brain atrophy.