By: Mark Torres Human Anatomy and Physiology II TR 3: Vitamin B12

Description Vitamin B12 is a water-soluble vitamin that can be found in some foods, dietary supplement and prescription medication. Only Vitamin not found in vegetables and contains cobalt. Absorption from GI tract depends on intrinsic factor secreted by gastric mucosa. First, hydrochloric acid in the stomach separates vitamin B12 from the protein to which vitamin B12 is attached in food. After this, vitamin B12 combines with a protein made by the stomach called intrinsic factor and is absorbed by the body.

Description Continue…. It is required for proper red blood cell formation, neurological function and DNA synthesis. Functions as an coenzyme needed for the formation of amino acid methionine, entrance of some amino acid into Krebs cycle and manufacture of choline (used to synthesize acetylcholine).

Recommended Dietary Allowance mcg = microgram

Food Sources B12 is naturally found in animal products including; Meat Liver Fish Eggs Poultry Dairy Products *Absent in Plant Food*

Deficiency Disease Pernicious anemia An autoimmune disease that affects gastric mucosa and results in gastric atrophy. Leads to destruction of parietal cell (secrete gastric aci and intrinsic factor), achlorhydria (low or zero production of gastric acid in stomach), and failure to produce intrinsic factor Neurologic disorder Neurological changes, such as numbness and tingling in the hands and feet, can also occur. Also difficulty maintaining balance, depression, confusion, dementia, poor memory, and soreness of the mouth or tongue

Overdose Disease There are no adverse effects associated with excess vitamin B12 intake