Vitamin B12 is said to have the largest and the most complex chemical structures of all the vitamins. It also contains a metal ion called cobalt and therefore it is called cobalamin. Hydrochloric acid which is present in the stomach releases
vitamin B12 from proteins in foods during the process of digestion and then it is absorbed by the intestinal tract.
Vitamin B12 is present in foods that can be found in fish, egg, milk, poultry and milk products. For vegetarians fortified cereals are an excellent source of vitamin B12. People above the age group of 50 should also derive their regular
vitamin B12 from fortified foods.
Vitamin B12 can be stored in small quantities within the body. It can store about 2-5mg in adults and about 80% of it is stored in the livers. It is released in the bile and is effectively reabsorbed. Therefore vegetarians who have a low intake of B12 get their daily dose from re-absorption than from foods.
It is not much of a problem to obtain your regular dose of vitamin B12 of 2.4 mcg per day. In the United States, the average intake of
vitamin B12 by young adult males is about 4.5 mcg per day while that of women is 3 mcg per day.
The main function of vitamin B12 is to form red blood cells and sustain a good nervous system. It is also important for the quick production of DNA during the process of cell division. So, if there is a deficiency of
vitamin B12 then there is a disruption of DNA production and irregular cells known as megaloblasts occur and results in anemia. Once this sets in you can experience symptoms of excessive tiredness, listlessness, pallor, breathlessness and reduced resistance to all kinds of infection. Some other symptoms that one can experience are tender tongue and menstrual disorders.
Another important function of B12 is maintaining a good nervous system. It plays a crucial function in the metabolism of fatty acids necessary for the protection of myelin. B12 deficiency for a long period can result in the degeneration of the nerve and irrevocable neurological damage.
The most common cause for
vitamin B12 deficiency is malabsorption and pernicious anemia, an autoimmune condition. Anemia occurs when there isn’t enough hemoglobin in the red blood cells to carry oxygen to tissues and cells. Anemia can result from a variety of deficiencies including vitamin B12, iron, folate and vitamin B6. Pernicious anemia is referred to the fatal vitamin B12 deficiency that occurs from severe gastric atrophy. This name was given several years ago. Individuals with
vitamin B12 deficiency suffer from stomach and intestine disorders. It has also been seen that people with low levels of B12 develop Alzheimer’s disease. Studies have also shown that as many as 30% people hospitalized for depression are deficient in vitamin B12. Vitamin B12 and its supplements are safe and no toxic or adverse effects have been reported with large intakes of vitamin B12. However, there are several drugs that lower the absorption of vitamin B12.
