The Importance of Vitamin B12 for our Body
Vitamin B12, also called cobalamin, is a water-soluble vitamin that is involved in the metabolism of every cell in the human body. It is particularly important in the normal functioning of the nervous system through its role in myelin synthesis and in the maturation of red blood cells in the bone marrow.
Vitamin B12, one of the eight water-soluble B vitamins, is the largest and most structurally complex vitamin. It exists as a complex in animal proteins and its main source is the microorganisms of the intestinal system of vegetarians.
Most people in developed countries get enough vitamin B12 from eating animal products, including meat, milk, eggs and fish. There are also foods that are fortified with vitamin B12. Vitamin B12 supplements are available in tablets of either single agent or multivitamin while the drugs can be administered by intramuscular injection.
The most common cause of vitamin B12 deficiency in developed countries is impaired absorption due to loss of gastric endogenous factor, which must bind to the B12 food source for absorption to occur. This condition is called malignant anemia. Nutritional deficiency of vitamin B12 is very rare in developed countries due to its adequacy in foods of animal origin but also in the existence of many foods fortified with vitamin B12.
Decreased intake of vitamin B12 can cause severe and irreversible damage, especially to the brain and nervous system. At levels only slightly lower than normal, a number of symptoms such as fatigue, lethargy, depression, poor memory, shortness of breath, headaches and pale skin may be observed, especially in the elderly (over 60 years) who produce less gastric acid in the stomach as they grow older, thus increasing the chance of B12 deficiency. Vitamin B12 deficiency can also cause symptoms of mania and psychosis.
Vitamin B12 deficiency is usually caused by low intake, but can also result from malabsorption, intestinal disorders, low protein binding and use of certain medications. Vitamin B12 is rare in plant-based products, so vegetarians are more likely to suffer from vitamin B12 deficiency. Babies are also at risk for vitamin B12 deficiency if they are born to vegetarian mothers. Elderly people whose diet is limited to meat or animal products are also vulnerable. Vitamin B12 deficiency can occur in between 40% and 80% of the vegetarian population.
Rich sources of vitamin B12 are liver, beef, lamb, fish, eggs and dairy products.