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Vitamin B-12
Vitamin B-12
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BASIC INFORMATIONVitamin B-12 is also called cyanocobalamin.
Brand names:
Cyanocobalamin Injectable Form -- Some doctors prescribe for home
use.
Anacobin(R)
Bedoz(R)
Berubigen(R)
Betalin 12(R)
Cyanabin(R)
Kaybovite-1000(R)
Redisol(R)
Rubion(R)
Rubramin PC(R)
Cyanocobalamin Tablets
Kaybovite(R)
Rubramin(R)
Hydroxocobalamin Injectable Form -- Some doctors prescribe for home
use.
Acti-B12(R)
alphaREDISOL(R)
Codroxomin(R)
Droxomin(R)
Available from natural sources? Yes
Available from synthetic sources? Yes
Prescription required? Yes, for high doses and injectable forms
Fat-soluble or water-soluble: Water-soluble
NATURAL SOURCES
Beef
Beef liver
Blue cheese
Clams
Eggs
Flounder
Herring
Liverwurst
Mackerel
Milk
Milk products
Sardines
Snapper
Swiss cheese
NOTE: Vitamin B-12 is not found in vegetables.
REASONS TO USE
Promotes normal growth and development.
Treats some types of nerve damage.
Treats pernicious anemia.
Treats and prevents vitamin B-12 deficiencies in people who
have had a portion of the gastrointestinal tract surgically
removed.
Prevents vitamin-B12 deficiency in vegan vegetarians and
persons with absorption diseases.
UNPROVED SPECULATED BENEFITS
Helps mental and nervous disorders.
Improves resistance to infection and disease.
Increases appetite.
Promotes growth of someone who has smaller-than-average
stature.
Improves memory and the ability to learn.
Increases energy.
WHO NEEDS ADDITIONAL AMOUNTS?
Strict vegetarians.
Anyone with inadequate caloric or nutritional dietary intake
or increased nutritional requirements.
Those who abuse alcohol or other drugs.
People with a chronic wasting illness, excess stress for long
periods or who have recently undergone surgery.
Those with a portion of the gastrointestinal tract surgically
removed.
People with recent severe burns or injuries.
DEFICIENCY SYMPTOMS
Pernicious anemia, with the following symptoms:
Fatigue, profound
Weakness, especially in arms and legs
Sore tongue
Nausea, appetite loss, weight loss
Bleeding gums
Numbness and tingling in hands and feet
Difficulty maintaining balance
Pale lips, pale tongue, pale gums
Yellow eyes and skin
Shortness of breath
Depression
Confusion and dementia
Headache
Poor memory
UNPROVED SPECULATED SYMPTOMS
Aging
Allergies
Eye problems
Slow growth
Skin problems
Easy fatigue
Mental symptoms
Sterility
Thyroid disorders
Menstrual disorders
Delusions and hallucinations
LAB TESTS TO DETECT DEFICIENCY
Serum vitamin B-12, a radioactive study usually performed with
serum-folic-acid test, called the Schilling Test
Reticulocyte count
DOSAGE AND USAGE INFORMATION
| Age |
RDA |
| 0-6 months |
0.5mcg |
| 6-12 months |
1.5mcg |
| 1-3 years |
2.0mcg |
| 4-6 years |
2.5mcg |
| 7-10 years |
3.0mcg |
| 11+ years |
3.0mcg |
| Pregnant |
+1.0mcg |
| Lactating |
+1.0mcg |
What this vitamin does:
Acts as co-enzyme for normal DNA synthesis.
Promotes normal fat and carbohydrate metabolism and protein
syntheses.
Promotes growth, cell development, blood-cell development,
manufacture of covering to nerve cells, maintenance of normal
function of nervous system.
Miscellaneous information:
There is a very low incidence of toxicity of vitamin B-12,
even with large amounts up to 1,000mcg/day.
Available as:
Oral and injectable forms. Oral forms are used only as diet
supplement. Only people with portions of the gastrointestinal
tract removed surgically or those with pernicious anemia require
injections.
Tablets: Swallow whole with full glass of liquid. Don't chew
or crush. Take with meals or 1 to 1-1/2 hours after meals unless
otherwise directed by your doctor.
Extended-release capsules or tablets: Swallow whole with full
glass of liquid. Don't chew or crush. Take with or immediately
after food to decrease stomach irritation.
Injectable forms are administered by doctor or nurse.
A constituent of many multivitamin/mineral preparations.
WARNINGS AND PRECAUTIONS
Don't take if you:
Are allergic to B-12 given by injection. Allergy to injections
produces itching, redness, swelling and rarely blood-pressure
drop with loss of consciousness.
Have Leber's disease.
Consult your doctor if you have:
Gout.
Over age 55:
No problems expected.
Pregnancy:
No problems expected.
Don't take megadoses.
Breast-feeding:
No problems expected.
Don't take megadoses.
Effect on lab tests:
Tests for serum potassium may show precipitous drop
(hypokalemia) during 48 hours after beginning treatment for
anemia.
Storage:
Store in cool, dry place away from direct light, but don't
freeze. Liquid forms should be refrigerated.
Store safely out of reach of children.
Don't store in bathroom medicine cabinet. Heat and moisture
may change action of vitamin.
Others:
The injectable form is the only effective form to treat
pernicious anemia or people with portions of the
gastrointestinal tract surgically removed. These individuals do
not absorb oral forms.
OVERDOSE/TOXICITY
Signs and symptoms:
If taken with large doses of vitamin C, vitamin B-12 may cause
nosebleed, ear bleeding, dry mouth.
What to do:
For symptoms of overdosage: Discontinue vitamin, and consult
doctor. Also see ADVERSE REACTIONS OR SIDE EFFECTS section
below.
For accidental overdosage (such as child taking entire
bottle): Dial 911 (emergency), 0 for operator or your nearest
Poison Control Center.
ADVERSE REACTIONS OR SIDE EFFECTS
| Reaction or effect |
What to do |
| Diarrhea (rare) |
Discontinue. Call doctor |
| |
immediately. |
| Itching skin after injections |
Seek emergency treatment. |
| (rare) |
INTERACTION WITH MEDICINE, VITAMINS OR MINERALS
| Interacts with |
Combined effect |
| Aminosalicylates |
Reduces absorption of vitamin |
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B-12. |
| Antibiotics |
May cause false-low test |
| |
results for vitamin B-12. |
| Ascorbic acid (vitamin C) |
Large doses may destroy |
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vitamin B-12. Separate doses |
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by at least 1 hour. |
| Chloramphenicol |
May prevent therapeutic |
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response when vitamin B-12 is |
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used to treat anemia. |
| Cholestyramine |
Reduces absorption of vitamin |
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B-12. |
| Colchicine |
Reduces absorption of vitamin |
| |
B-12. |
| Folic acid |
Large doses decrease vitamin |
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B-12 concentrations in blood. |
| Neomycin (oral forms only) |
Reduces absorption of vitamin |
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B-12. |
| Potassium in extended-release |
Reduces absorption of vitamin |
| forms B-12. |
May increase need for |
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vitamin B-12. |
INTERACTION WITH OTHER SUBSTANCES
Tobacco decreases absorption. Smokers may require supplemental
vitamin B-12.
Alcohol in excessive amounts for long periods may lead to
vitamin B-12 deficiency.
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From Complete Guide to Vitamins, Minerals & Supplements by H. Winter Griffith, M.D. Copyright by Putnam Publishing
Group. Electronic rights by Medical Data Exchange.
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