Vitamin B12, also known as Cobalamin, is essential for normal nerve cell activity, DNA replication, & the production of a mood-enhancing substance called SAMe (S-adenosyl-L-methionine). As many as 20% of adults may be deficient in vitamin b 12, & as we get older or more stressed, our ability to absorb it reduces. Being water-soluble vitamin B12 should be replaced on a daily basis. Vitamin B12, Folic Acid and vitamin B6 work hand in hand with each other to control homocysteine levels, preventing many heart disease problems such as angina & strokes. On its own B12 is still very powerful when it comes to elevating mood by the production of SAMe, which also has an effect on depression, insomnia & cognitive decline like Alzheimers disease. Recently B12 has been shown to have a positive effect on energy levels; in one trial boosting levels by 80% in a group of Chronic Fatigue Syndrome sufferers, this may because of the effect it has on anaemia & the transportation of red blood cells around the body for proper oxygenation. Many researchers & healthcare professionals believe that we can't rely on vegetarian sources of this amazing nutrient, so a supplement is essential.