|
Belonging to the B complex group, vitamin B12 is a water soluble vitamin, containing cobalt. It plays a vital role in the proper functioning of the nervous system and the brain. It is essential for the formation of blood and the metabolism of each cell and is especially responsible for the regulation and synthesis of DNA - the genetic material in each cell. It is needed for the normal development and growth of children. It plays an important role in the synthesis of fatty acids and the production of the energy needed by the body. Vitamin B12 is bound to the proteins we eat and the hydrochloric acid in the stomach helps to release B12 from the proteins during digestion. Before being absorbed into the blood stream, B12 combines with a substance in the body called Intrinsic Factor.
A slight deficiency of this vitamin can cause poor memory, fatigue and depression. Complete deficiency of vitamin B12 can cause severe damage to the brain and nervous system which may be irreversible. However, a deficiency of this vitamin is extremely rare as the body is capable of storing a large amount of vitamin B12. The deficiency may arise as a result of the body not being able to use this vitamin due to an illness called pernicious anemia, where the body lacks in the intrinsic factor needed for absorption of the vitamin. This is seen normally in elderly people. Strict vegetarians may not get adequate amounts as vitamin B12, as it is found only in some vegetarian foods in a form that cannot be used by humans. However, sufficient quantities of folic acid are known to mask vitamin B12 deficiencies to some extent.
The sources of vitamin B12 are limited. B12 is found in abundance in shellfish, eggs, meat and dairy products like milk and cheese and these foods are the only reliable unfortified source of B12. However, eggs also contain a factor that blocks the absorption of B12. Boiling milk and fermenting yogurt lead to a significant loss of the vitamin. Some breakfast cereals, raisin bran, vegetable and sunflower margarine and some soy products are fortified sources of vitamin B12. However, it is important to note that soy products have some repercussions on the body. Studies show that the algae spirulina which is available in tablet form as a dietary supplement and seaweeds, nori and laver, barley grass and human gut bacteria have significant traces of B12, but these sources are highly unreliable for use in preventing a deficiency of vitamin B12.
|
