what is vitamin B12 cobalamin sources of vitamin B12 benefits of vitamin B12 india4indians.com

What is Vitamin B12 | Vitamin B12 (cobalamin) | What are the Sources of Vitamin B12 | What are the Benefits of Vitamin B12

• Vitamin B12, also called cobalamin, is a water soluble vitamin with a key role in the normal functioning of the brain and nervous system, and for the formation of blood. It is one of the eight B vitamins. It is normally involved in the metabolism of every cell of the body, especially affecting DNA synthesis and regulation, but also fatty acid synthesis and energy production.
• One coenzyme form of B12 is called methylcobalamin and with the help of folic acid, can donate its methyl group to convert homocysteine (high levels are a risk factor for heart disease) to methionine. The other, adenosylcobalamin, is involved in the breakdown of certain fatty acids and in the synthesis of amino acid, leucine.
• B12 also participates in the body’s regeneration of folic acid. Without Bj2, we would be unable to efficiently use acid in our bodies and would require such massive amounts of that vitamin that we probably couldn’t get enough from food sources. This regeneration reaction involves the metabolism of homocysteine. Suffice to say that we need to get ample B6, B12, and folic acid so that damaging homocysteine does not build up in our bodies.
• About 30 mcg of vitamin B12 are excreted in the normal urine daily. When injected in a large dose upto 100 mcg, upto 90 per cent of the quantity is excreted. Since the absorption of vitamin B12 does not take place in the colon, much of the unabsorbed vitamin B12 is excreted in the stools. This vitamin is also secreted in breast milk for the use of babies.
• Cobalamin, which contains the trace mineral cobalt, is the natural form of B12. But the commonly available form of B12, cyanocobalamin, is not found in nature. It was accidentally discovered by a pharmaceutical researcher attempting to purify cobalamin. Cyanocobalamin is the most convenient way to supplement your B12 intake because of its stability.
• On the other hand, hydroxycobalamin, the chemical precursor to cyanocobalamin, is sometimes preferable to cyanocobalamin and offers some advantages to people with a proven B12 deficiency. It is absorbed more slowly than cyanocobalamin after injection into a muscle and is stored in larger quantities by the liver. Hydroxycobalamin produces a more sustained rise in B12 levels and is eliminated more slowly from the body.

WHAT ARE THE SOURCES OF VITAMIN B12 (cobalamin) ?

Good sources are liver, kidney, meat, fish, eggs, milk and cheese.

1. Vitamin B12 is not found in foods of vegetable origin. Bacteria in colon also synthesize it. Unlike folic acid, vitamin B12 is heat stable. Liver is the main storage site of vitamin B12. About 2 mg are stored in the liver and another 2 mg elsewhere in the body.

2. Good sources of vitamin B12 for vegetarians are dairy products or free-range eggs. ½ pint of milk (full fat or semi skimmed) contains 1.2 µg. A slice of vegetarian cheddar cheese (40g) contains 0.5 µg.

3. A boiled egg contains 0.7 µg. Fermentation in the manufacture of yoghurt destroys much of the B12 present. Boiling milk can also destroy much of the B12.

4. Vegetarians are advised that they should ensure their diet includes foods fortified with vitamin B12. These include yeast extracts, Vecon vegetable stock, veggie burger mixes, textured vegetable protein, Soya milks, vegetable and sunflower margarines, and breakfast cereals.

5. This vitamin is found in the fungus Streptomyces griseus.

WHAT ARE THE BENEFITS OF VITAMIN B12 (COBALAMIN) ?

1. Vitamin B12 is essential for the production and regeneration of red blood cells.
2. It is also needed for the proper functioning of the central nervous system.
3. It improves concentration, memory, and balance, and relieves irritability.
4. Vitamin B12 is necessary for proper utilisation of fats, carbohydrates, and proteins for body building.
5. It promotes growth and increases appetite in children.
6. This vitamin is also involved in many vital metabolic ,and enzymatic processes, including the metabolism of folic acid. If the immune cells made in the bone marrow are to mature into active disease-fighters, a sufficient quantity of vitamin B12 and folic acid are necessary.