Vitamin B12 Deficiency

U.S. Army Health Clinic, Darmstadt, Germany.
American family physician (Impact Factor: 2.18). 04/2003; 67(5):979-86.
Source: PubMed


Vitamin B12 (cobalamin) deficiency is a common cause of macrocytic anemia and has been implicated in a spectrum of neuropsychiatric disorders. The role of B12 deficiency in hyperhomocysteinemia and the promotion of atherosclerosis is only now being explored. Diagnosis of vitamin B12 deficiency is typically based on measurement of serum vitamin B12 levels; however, about 50 percent of patients with subclinical disease have normal B12 levels. A more sensitive method of screening for vitamin B12 deficiency is measurement of serum methylmalonic acid and homocysteine levels, which are increased early in vitamin B12 deficiency. Use of the Schilling test for detection of pernicious anemia has been supplanted for the most part by serologic testing for parietal cell and intrinsic factor antibodies. Contrary to prevailing medical practice, studies show that supplementation with oral vitamin B12 is a safe and effective treatment for the B12 deficiency state. Even when intrinsic factor is not present to aid in the absorption of vitamin B12 (pernicious anemia) or in other diseases that affect the usual absorption sites in the terminal ileum, oral therapy remains effective.

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    • "The human body requires vitamin B 12 in order to maintain a variety of processes vital to health and maintenance among which are cell reproduction and growth, and nucleoprotein and myelin synthesis [5]. In the nervous system, vitamin B 12 plays a role in nerve metabolism via the remethylation of homocysteine to methionine for de novo synthesis of sadenosylmethionine [6]. One of the mechanisms believed to be at play in vitamin B 12 deficiency neuropathy is hypomethylation in the central nervous system. "

    International Journal of Scientific & Technology Research 11/2015; · 0.68 Impact Factor
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    • "The deficiency of Vitamin B 12 may cause some disorders such as hematologic, neuropsychiatric and cardiovascular disorders. According to the clinical findings, patients whose blood serum levels of Vitamin B 12 are lower than 200 pg/mL (150 pmol/L) are diagnosed with Vitamin B 12 deficiency [35]. Therefore, the determination of the level of Vitamin B 12 is very important for blood, drugs, dairy products, and fermentation products . "
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