Vitamin B12, Total Unit Converter

Vitamin B12, also known as cobalamin, is a water-soluble vitamin essential for many bodily functions. It plays a critical role in DNA synthesis, red blood cell formation, and the normal functioning of the nervous system.

Total vitamin B12 measures the combined amount of all forms of B12 in your blood, including both the active form (holotranscobalamin) and inactive forms bound to haptocorrin. Only about 20% of total B12 is in the active, bioavailable form.

The body stores large amounts of B12 in the liver (enough to last several years), which is why deficiency symptoms often develop slowly over months to years.

Vitamin B12 is obtained exclusively from animal products such as red meat, fish, poultry, eggs, and dairy. It is absorbed in the terminal ileum after binding to intrinsic factor, a protein produced by stomach parietal cells, and is primarily stored in the liver.