Vitamin B12, also known as cobalamin, is a water-soluble vitamin that is essential for several critical physiological processes. It has a key role in the normal functioning of the brain and nervous system, and for the formation of blood. It’s involved in the metabolism of every cell of the human body, especially affecting DNA synthesis and regulation, fatty acid synthesis, and energy production.

B12 is unique among vitamins because it contains a metal ion, cobalt. This is why compounds with vitamin B12 activity are collectively called “cobalamins”. The vitamin is produced by bacteria and is not made by plants or animals. Humans get it from dietary sources that include animal-based foods such as meat, fish, milk, cheese, and eggs.

Deficiency in B12 can lead to various health issues, including anemia, neurological disturbances, and potential cardiovascular disease. The early detection and treatment of B12 deficiency are important because if left untreated, the neurological complications can become permanent.

People who may be at a higher risk for B12 deficiency include older adults, those with gastrointestinal disorders, vegetarians and vegans, and those who have had gastrointestinal surgery. Supplementation with B12 may be advised for these groups, and it can be administered orally, through fortified foods, or by injection in cases where absorption may be impaired.