Vitamin B12 is a water-soluble vitamin. Cobalamin is the term used to refer to compounds having vitamin B12 activity.
Vitamin B12 requires a protein in the gastrointestinal tract that aids in absorption (intrinsic factor).
Hydrochloric acid also is necessary to split vitamin B12 from its peptide bonds. Atrophic gastritis results in a low acid-pepsin secretion by the gastric mucosa, which in turn results in a reduced release of free vitamin B12 from food protein to be absorbed. This condition is associated with advanced age.
Absorption of protein-bound vitamin B12 decreases with age or deficiency of iron or folic acid, and increases during pregnancy.
The body stores 2000 to 5000 mcg, primarily in the liver and kidneys, and excesses are excreted by way of kidney or in bile.
Vitamin B12 is connected to a conenzyme form and is essential for normal metabolism in all cells especially those of the gastrointestinal tract, bone marrow, and nervous system. The vitamin also functions in the transfer of methyl groups in the synthesis of nucleic acids, purines, and pyrimidine intermediates. Red blood cell formation and control of pernicious anemia.
Protein, fat, and carbohydrate metabolism.Converting homocysteine to methionine. Neurotransmitter synthesis.
Vitamin B12 alters neurotransmitter synthesis through S-adenosylmethionine.
Vitamins B12, B6 and folic acid work together to provide methyl groups in biological pathways and reduce homocysteine.
Injectable form may have better absobtion.