Knowing About Vitamin B12 Deficiency
By Sam Cyrus

A vitamin B12 deficiency reflects a chronic shortage of the vitamin B12. The vitamin B12 (cobalamin) is necessary for normal red blood cell formation, tissue and cellular repair, neurologic function, and DNA synthesis. The vitamin B12 deficiency can lead to a wide spectrum of hematologic and neuropsychiatric disorders that can often be reversed by early diagnosis and prompt treatment.

Since the body stores 3 to 5 years worth of the vitamin B12 and several months’ supply of folate in the liver, deficiencies and their associated symptoms can take months to years to manifest in adults. Infants and children will show signs of deficiency more rapidly, however, as they have not yet established extensive reserves.

Vitamin B12 deficiency is a common cause of macrocytic anemia and has been implicated in a spectrum of neuropsychiatric disorders. The role of the vitamin 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. 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 vitamin B12 deficiency state.

Over time, the vitamin B12 deficiency or folate deficiency can lead to macrocytic anemia, a condition characterized by the production of fewer, but larger red blood cells and a decreased ability to carry oxygen. Due to the anemia, patients may be weak, light-headed, and short of breath. The vitamin B12 deficiency can also result in varying degrees of neuropathy, nerve damage that can cause tingling and numbness in the patient’s hands and feet and mental changes that range from confusion and irritability to severe dementia.