Vitamin B12 is important for metabolism. It helps in the formation of red blood cells, production of energy and in the maintenance of the central nervous system. B12 also supports the normal brain function.
While vitamins can be obtained from the diet, B and C vitamins are easily lost or eliminated during cooking or processing.
Many people over age 50 lose the ability to absorb vitamin B12 from foods. Moreover people who have had gastrointestinal surgery or have digestive disorders may not absorb vitamin B12 adequately.
The eight vitamins that make up the B complex are water soluble, meaning the body does not store excess amounts of any of the B vitamins except vitamin B12, which is stored in the liver. The other unused B vitamins are excreted through urine. This means you need a continuous supply of the B vitamins from your diet.