DESCRIPTION
Vitamin B12 tablets, provided by Douglas
Laboratories, supply 500 mcg of Vitamin B-12 in
each easy to swallow tablet.
FUNCTIONS
Vitamin B12 is essential for normal energy
metabolism of carbohydrate, fat and protein. As a
cofactor for methylmalonyl-CoA mutase enzymes,
vitamin B12 helps convert odd chain fatty acids and
branched chain amino acids into succinyl-CoA, a
common citric acid cycle intermediate. Vitamin B12
is also required for nucleic acid (DNA) synthesis,
methionine synthesis from cysteine, and normal
myelin synthesis in the nervous system. Along with
vitamin B6 and folic acid, adequate levels of vitamin
B12 are required to maintain normal plasma
homocysteine levels. Elevated plasma homocysteine
may be an independent risk factor for developing
cardiovascular disease.
There are two distinct mechanisms for intestinal
vitamin B12 absorption; receptor-mediated absorption
and passive diffusion. In the first, vitamin B12 attaches
to a salivary ¡§R-binder¡¨ protein which transports it
into the small intestine, where vitamin B12 is released.
The vitamin then binds to ¡§Intrinsic Factor¡¨ (IF), a
glycoprotein normally produced by the gastric parietal
cells. This vitamin B12-IF complex is carried down to
the ileum, where it binds to mucosal receptors.
Finally, the complex is absorbed and bound to serum
vitamin B12-binding proteins. The second absorption
mechanism, passive diffusion, does not require any
carriers, such as B-binder or IF. Only about 1% of
free vitamin B12 is passively absorbed, but this can be
nutritionally significant with higher dietary vitamin
B12 intakes.
Almost 40% of the population is suggested to have
¡§low normal¡¨ plasma B12 levels. Strict vegetarians,
the elderly, and, HIV/AIDS patients are often at risk
for vitamin B12 deficiency, either due to low dietary
intake or impaired absorption. In the elderly, hypo- or
achlorhydria maintains the binding of the vitamin
with dietary proteins, leading to malabsorption.
Vitamin B12 deficiency can lead to CNS impairment,
including cognition.
INDICATIONS
Vitamin B-12 may be a useful dietary supplement for
individuals who wish to increase their intake of
vitamin B12.
FORMULA
1 Tablet Contains:
Vitamin B-12 500 mcg
SUGGESTED USE
Adults take 1 tablet daily or as directed by physician.
SIDE EFFECTS
No adverse side effects reported.
STORAGE
Store in a cool, dry place, away from direct light.
Keep out of reach of children.
