Sources of Vitamin B12

Vitamin B12, a water soluble vitamin has one of the most complicated structures among all the vitamins. This vitamin is required by the body for the formation of red blood cells, cell division and proper development of nerve cells. It also plays an important role in carbohydrate, protein and fat metabolism. An interesting fact about this vitamin is that it cannot be produced by animals or plants. Only microorganisms like yeasts, bacteria, molds and fungi possess the ability to produce this vitamin. In animal body, microorganisms found in the large intestine are responsible for producing vitamin B12.

Proper utilization of vitamin B12 mainly depends on a substance known as 'intrinsic factor', a protein produced in the stomach. In the absence of this substance, vitamin B12 cannot be absorbed by the body. Deficiency of this crucial vitamin may trigger symptoms like nervousness, numbness / tingling sensation in the feet, depression, fatigue, memory problems, menstrual problems in women, heart palpitation, general weakness, etc.

Food Sources of Vitamin B12
It has been found that the animals can store more vitamin B12 than plants. In animals, liver is the main storage organ of vitamin B12. So, liver of animals is a good source of this vitamin. Calf's liver and snappers are said to be excellent sources of this vitamin. Besides, a substantial amount of vitamin B12 can also be derived from beef, scallops, salmons, tuna, shrimp, boiled eggs, cow's milk, yogurt, etc.

Plant foods are not a very rich source of vitamin B12, as they can neither produce nor store it as much as the animals can. So, the amount of vitamin B12 in plants mainly depends on the microorganisms found in the roots of the plants, and in the soil in which they are grown. Some plant sources of this vitamin include fermented and cultured products like miso, tofu, tempeh,
tamari, shoyu, fortified cereals and nutritional yeasts. Sea vegetables and seaweeds like algae also contain vitamin B12, depending on the quantity of microorganisms that exist in the surrounding environment. Supplements of this vitamin are also available in the market. In most of the supplements, vitamin B12 is found as cyanocobalamin.

Deficiency of vitamin B12 can cause some severe diseases like anemia and nerve damage. The deficiency mainly occurs due to two factors, stomach problems or low level of acid in the stomach. Generally, problems like inflammation and irritation of the stomach disrupt the normal functioning of the stomach cells. This in turn, hinders the production of the substance 'intrinsic factor', required for the absorption of vitamin B12. Similarly, acids produced in the stomach also play a significant role in the absorption of this vitamin, by releasing the same from proteins in the foods. Besides this, some other vitamins are also required for proper utilization of vitamin B12. Vitamin B6 is required for absorption, while Vitamin E is needed for conversion of the non-active form of vitamin B12 into the active form. Therefore, in addition to sufficient intake of this vitamin, all these factors should also be taken into consideration to ensure its proper utilization.