Deficiencies in Vitamin B12 tend to show up in later life after 50. Small deficiencies can lead to increased risk of heart disease, depression and even possibly Alzheimer’s disease. Vitamin B12 is the only B-vitamin which is stored in high levels in the liver. Vitamin B12’s key role is for the proper functioning of the nervous system, including the brain. It is also needed for the formation of red blood cells; DNA synthesis and metabolism of every single cell in the body. There are many symptoms which are related to low levels of vitamin B12: depression; fatigue; numbness; tingling in the extremities which is caused by nerve damage; memory loss and confusion. The recommended dose of Vitamin B12 is 1000mcg along with 400mcg of folic acid.