Vitamin B12 is important for maintaining a healthy metabolism, blood cells, and nerves. Certain health conditions or life styles can cause a deficiency in Vitamin B12, also called Cyanocobalamin. These include following a strict vegan diet, alcoholism, intestinal or stomach problems, an HIV infection, pregnancy, or just going through old age.Taking Vitamin B12 1000mcg Sublingual (Jamieson) is easy as you simply place it under your tongue and let is dissolve and enter your blood stream faster than swallowing a tablet or capsule.