Like HowStuffWorks on Facebook!

How Vitamin B12 Works

Vitamin B12 Supplements
Physicians usually treat pernicious anemia with an injection of anywhere from 50 to 100 mcg of vitamin B12 three times a week. These injections may need to continue throughout life. However, medical studies show that large amounts of active vitamin B12 can be absorbed, even without intrinsic factor.

Huge amounts of vitmain B12 are needed to offset deficiency.
© 2007 Publications International, Ltd.
Because B12 deficiency is usually the result of the body's inability to absorb it,
huge amounts are needed to offset this condition.

The form of vitamin B12 called methylcobalamin is the only active form sold in the United States. Cyanocobalamin, a more commonly available form, requires modification in the body, and even then, when used in studies, it is not always effective. Methylcobalamin, when given in very large doses, can be absorbed.

There are supplements that are meant to be taken under the tongue. Sublingual administration is thought to bypass the absorption problems related to the intrinsic factor by allowing the vitamin to be absorbed directly into the venous plexus -- the complex of blood vessels located in the floor of the mouth.
To find great prices on B vitamins, click here.

Huge amounts of the vitamin ensure that at least some of it gets absorbed, even without intrinsic factor; 1,000 mcg per day is a common recommendation, sometimes starting with 2,000 mcg per day for the first month. There are no reports of vitamin B12 causing toxicity or adverse effects even in these large amounts. In fact, it is often used as a placebo because of its assured non-toxicity.

As you can see, vitamin B12 just doesn't quite act the same as other vitamins. After reading this article, you'll be able to understand it better and its importance in your diet.

Vitamin B12 is just one of the many vitamins that are part of a healthy diet. Check out the following links to learn more:
  • Vitamin B1, or thiamin, is one of the essentil vitamins added back to "enriched" foods. Learn about it at How Vitamin B1 Works.
  • Relax; you'll find the stress-busting Vitamin B5 in every food you eat. Learn about it at How Vitamin B5 Works.
  • Biotin aids in metabolism, turning food into energy. Learn more at How Biotin Works.
  • Your body can make its own Vitamin D if you get enough sunshine. Learn the details at How Vitamin D Works.
  • Vitamin K plays a vital role in blood clotting. Learn more at How Vitamin K Works.
  • To learn about the many vitamins in our diet, how much you should be eating, and where to find them, go to our general Vitamins page.
  • If you're looking for the best prices on B vitamins, click here.

Jennifer Brett, N.D. is director of the
Acupuncture Institute for the University of Bridgeport, where she also serves on the faculty for the College of Naturopathic Medicine. A recognized leader in her field with an extensive background in treating a wide variety of disorders utilizing nutritional and botanical remedies, Dr. Brett has appeared on WABC TV (NYC) and on Good Morning America to discuss utilizing herbs for health.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.