THE IMPORTANCE OF VITAMIN B-12
Vitamin B12
Vitamin B 12 is a key nutritional element to human health.
What is vitamin B12?
Vitamin B12, also known as cobalamin, is a necessary co-factor in a variety of metabolic processes. It supports the synthesis of red and white blood cells, as well as the production and maintenance of healthy nerve cell membranes.
Cobalamin cannot be synthesized by the human organism; it must be ingested. Fortunately, this vitamin is ubiquitous in foods derived from animals.
Unlike other B vitamins, for which the body generally has only a few weeks to months of inventory, humans are capable of storing substantial quantities of vitamin B12, primarily in the liver. Younger adults have anywhere from a 2 to 3 year supply in reserve. .
B12 is the only vitamin that has a heavy metal ion – cobalt – in its structure. A more detailed discussion of vitamin B12 and its common dietary sources can be found at the NIH's office of dietary supplements, http://ods.od.nih.gov/index.aspx. Then type in "vitamin B12" in the search box.
What diseases and symptoms are related to a deficiency of vitamin B12?
This essential vitamin was first identified in the early part of the 20th century as the result of an intensive investigation of the illness called “Pernicious Anemia” and its causes. As tests became available to measure this compound, additional disorders were found to be associated with a deficit of B12, including constipation, fatigue and depression. A persistent deficiency can cause a variety of subtle neurologic symptoms, including tingling sensations, balance issues and even a decrease in cognitive capacity.
How is vitamin B12 absorbed by the body?
Several steps are necessary before the body can make use of vitamin B12 once it is ingested in a meal. In a healthy person, stomach acid releases B12 from the proteins to which it is bound. It then combines with a substance produced by the stomach called “intrinsic factor” , and is absorbed in the final section of the small intestine, called the ileum. It is noteworthy that only 6 micrograms of vitamin B12 is required on a daily basis.
Who is at risk of becoming deficient?
As might be inferred from the description of the absorption process, patients with a diseased or absent distal portion of the small intestine (for example, in the case of Crohn’s disease) are particularly susceptible to vitamin B12 deficiency. Also at higher risk are strict vegetarians, as well as persons with a form of chronic gastritis, which causes inflammation and atrophy of the stomach glands. Others who may be at higher risk are those people who have had stomach surgeries, including the growing number of patients who have undergone gastric banding for the management of morbid obesity.
How are deficiencies treated?
In the past, patients with pernicious anemia in particular were treated with monthly injections. Now, with the availability of high dose oral B12, most patients can be managed with a daily supplement, ranging from 500 to 1000 micrograms. Dosages of this magnitude are required because the body can only absorb about 1% of this form of the vitamin.
Your Concorde doctor can check vitamin B12 levels as part of your annual physical, and more often if you have already had supplements prescribed. As always, if you are concerned that you may have a deficiency, please do not hesitate to consult with your physician.
