Vitamin B 12

Vitamin B₁₂, vitamin B12 or vitamin B-12, 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 human body, especially affecting DNA synthesis and regulation, but also fatty acid synthesis and energy production. Neither fungi, plants nor animals are capable of producing vitamin B₁₂. Only bacteria and archaea have the enzymes required for its synthesis, although many foods are a natural source of B₁₂ because of bacterial symbiosis. The vitamin is the largest and most structurally complicated vitamin and can be produced industrially only through bacterial fermentation-synthesis.

Vitamin B12 is naturally found in animal products, including fish, meat, poultry, eggs, milk, and milk products. Vitamin B12 is generally not present in plant foods, but fortified breakfast cereals are a readily available source of vitamin B12 with high bioavailability for vegetarians  Some nutritional yeast products also contain vitamin B12. Fortified foods vary in formulation, so it is important to read product labels to determine which added nutrients they contain.

Vitamin B₁₂ deficiency can potentially cause severe and irreversible damage, especially to the brain and nervous system. At levels only slightly lower than normal, a range of symptoms such as fatigue, depression, and poor memory may be experienced.

Vitamin B₁₂ deficiency can also cause symptoms of mania and psychosis. Vitamin B₁₂ deficiency can be caused by the metabolic disorder pernicious anemia.

1. Clams, Oysters, and Mussels 
2. Liver 
3.  Caviar (Fish Eggs) 
4. Octopus
5.  fish 
6. lamb
7.  cheese

Contains Vitamin B12