Your Health and Avoid Side Effects When Using Com-
mon Medications and Natural Supplements Together.
New York: Three Rivers Press, 2006.
Lieberman, Shari and Nancy Bruning.The Real Vitamin and
Mineral Book: The Definitive Guide to Designing Your Per-
sonal Supplement Program,4th ed. New York: Avery, 2007.
Pressman, Alan H. and Sheila Buff.The Complete Idiot’s
Guide to Vitamins and Minerals,3rd ed. Indianapolis,
IN: Alpha Books, 2007.
Rucker, Robert B., ed.Handbook of Vitamins.Boca Raton,
FL: Taylor & Francis, 2007.
ORGANIZATIONS
American Cancer Society. 1599 Clifton Road NE, Atlanta
GA 30329-4251. Telephone: 800 ACS-2345. Website:
http://www.cancer.org
American Dietetic Association. 120 South Riverside Plaza,
Suite 2000, Chicago, Illinois 60606-6995. Telephone:
(800) 877-1600. Website:http://www.eatright.org
Linus Pauling Institute. Oregon State University, 571
Weniger Hall, Corvallis, OR 97331-6512. Telephone:
(541) 717-5075. Fax: (541) 737-5077. Website:http://
lpi.oregonstate.edu
Office of Dietary Supplements, National Institutes of
Health. 6100 Executive Blvd., Room 3B01, MSC 7517,
Bethesda, MD 20892-7517 Telephone: (301)435-2920.
Fax: (301)480-1845. Website:http://dietary-
supplements.info.nih.gov
OTHER
American Cancer Society ‘‘Vitamin B Complex.’’ American
Cancer Society, October 6, 2005.<http://www.cancer.
org/docroot/ETO/content/ETO_5_3X_Vitamin_B 6.
asp?sitearea=ETO>.
Frye, Richard E. ‘‘Pyridoxine Deficiency.’’ emedicine.com,
July 11, 2006.http://www.emedicine.com/med/
topic1977.htm.
Higdon, Jane. ‘‘Vitamin B 6 .’’Linus Pauling Institute-Oregon
State University, February 19, 2002.<http://lpi.oregon
state.edu/infocenter/vitamins/VitaminB 6 >.
Harvard School of Public Health. ‘‘Vitamins.’’ Harvard Uni-
versity, November 10, 2006.http://www.hsph.harvard.
edu/nutritionsource/vitamins.html.
Maryland Medical Center Programs Center for Integrative
Medicine. ‘‘Vitamin B 6 (Pyridoxine).’’ University of
Maryland Medical Center, April 2002.<http://www
.umm.edu/altmed/ConsSupplements/VitaminB 6
Pyroxidinecs.html>.
Medline Plus. ‘‘Vitamin B 6 .’’ U. S. National Library of
Medicine, September 1, 2006.<http://www.nlm.nih/
gov/medlineplus/druginfo/natural/patient-B 6 .html>.
Office of Dietary Supplements. ’’Dietary Supplement Fact
Sheet: Vitamin B 6 .‘‘ National Institutes of Health,
January 11, 2007. http://ods.od.nih.gov/factsheets/
vitamindB 6 asp/.
Tish Davidson, A.M.Vitamin B 9 seeFolate
Vitamin B 12
DefinitionVitamin B 12 is a water-soluble organic compound
that the body needs to remain healthy. The only organ-
isms that can make vitamin B 12 are bacteria, fungi,
yeast, molds, and algae. Humans must get it from
foods in their diet. Vitamin B 12 is sometimes called
cobalamin.Purpose
Vitamin B 12 plays major roles in developing healthy
red blood cells, creating new deoxyribose nucleic acid
(DNA, genetic material), and in maintaining the health
of nerve cells. It is also involved in making certain
nutrients available to the body.Description
Vitamin B 12 is one of the least understoodvita-
mins. Although some of its effects were experimentally
discovered in the 1930s, Vitamin B 12 ’s structure was
not determined until the 1960s. Questions still remain
about some of its functions. Vitamin B 12 is different
from other vitamins in several ways. It is the only
vitamin not made by any plant or animal, but only
by microorganisms. It is the only vitamin to contain
the metal cobalt (thus the name cobalamin), and it is
the only vitamin that must combine with another sub-
stance, called the intrinsic factor (IF), before it can be
absorbed by the body.
Although vitamin B 12 is made only by microor-
ganisms, it is found in association with animalprotein.
In nature, it comes in a variety of chemical forms that
the body converts into two active forms of B 12. Most
B 12 dietary supplementscontain the form called cya-
nocobalamin. B 12 is included in over-the-counter mul-
tivitamins and in vitamin-B-complex supplements. It
is also sold as a stand-alone dietary supplement and in
an injectable form available only by prescription.
When people eat animal protein-beef, fish, pork,
chicken, eggs, milk, cheese-the stomach is stimulated
to secrete hydrochloric acid and enzymes that break
down the protein and release vitamin B 12 .B 12 then
binds with IF, which is made in the stomach. Vitamin
B 12 cannot be absorbed into the body unless it is
combined with IF. Therefore, either an absence of
B 12 in diet or inability of the stomach to make IF can
result in B 12 deficiency.
Some fermented bean products such as tofu, tem-
peh, natto, tamari, and miso may or may not containVitamin B12