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VITAMIN B12: FUNCTIONS & NEW NASAL SPRAY
Laura Power, M.S., Ph.D., L.N.
© 2006
B12
Vitamin B12 is a common deficiency among my patients. This includes children with developmental delays,
adults with heart disease or macrocytic anemia, and senior citizens. B12 is also not easily absorbed or metabolized.
Hence tablets do not always work well. So I have arranged for a custom compounded vitamin B12 (as pre-metabolized
methyl-cobalamin) to be delivered by metered nasal spray. Let us look at the functions and therapies for vitamin
B12 more closely.
WHAT IS VITAMIN B12?
Vitamin B12 is part of the B-complex family of vitamins. It is a large complex molecule, with the metal cobalt at
the center, surrounded by a ring-like molecule, and so is called a “cobalamin”.
The common food form of B12 is cyano-cobalamin. B12 is bound to protein in food, and must be separated by stomach
acid, then bound to intrinsic factor in the stomach, then bound to R-protein in the intestines, then it must be
metabolized in the liver to methyl-cobalamin for cells to use. So you can see that it is very complex to absorb
and metabolize. Not everyone can do this efficiently. Certain groups of people have defects of one kind or another
that interfere with this. And these people need extra vitamin B12 in a pre-metabolized form.
FUNCTION & DEFICIENCY SIGNS
Vitamin B12 has several key functions in the body:
- B12 helps build healthy red blood cells. Along with folic acid it helps the red blood cells divide. A deficiency of B12 or folate can cause macrocytic, megaloblastic, or pernicious anemia.
- B12 helps maintain healthy nerve cells by building the myelin sheath around the nerves. Deficiencies have been associated with neurological symptoms: numbness and tingling in hands and feet, poor balance and coordination, confusion, short-term memory loss, a spacey feeling, senile dementia, regressive autism, psychosis, multiple sclerosis, depression,
- B12 is also needed to help make DNA, the genetic material in all cells.
- B12 is a “methyl donor”, and as such is important in Phase 2 liver detoxification.
- Deficiencies of B12, folate, or vitamin B6 can cause high levels of homocysteine, which is a 15 times greater predictor of heart disease than high cholesterol.
- General deficiency signs include: fatigue, weakness, constipation, loss of appetite, weight loss, and soreness of the mouth or tongue.
- Deficiency signs in infants include: failure to thrive, movement disorders, delayed development, and macrocytic anemia.
WHO HAS SPECIAL NEEDS FOR VITAMIN B12?
- People with macrocytic or pernicious anemia.
- Children and adults with regressive autism.
- People with multiple sclerosis.
- People with short-term memory loss, senile dementia, or psychosis.
- The elderly, and 30% of people over age 50.
- People with digestive problems: gastric problems (low stomach acid), celiac disease, malabsorption, or Crohn’s disease.
- People with certain kinds of liver problems, toxemia, or chemical sensitivities.
- People with heart disease.
- Vegetarians.
- Pregnant or lactating women.
- People with Addison’s disease.
- Patients taking these drugs, which interfere with B12 digestion, absorption or metabolism, including: Omeprazole (Prilosec©), Lansoprazole (Prevacid©), Tagament©, Pepsid©, Zantac©, and Metformin©.
- People taking excessive folic acid without vitamin B12. This may cure the macrocytic anemia, but mask an underlying neurological disease.
WHAT FOODS PROVIDE VITAMIN B12?
Vitamin B12 is made by bacteria. It is found in animal foods, but not in plant foods. It is naturally found in the
following foods: mollusks, clams, fish, beef, beef liver, pork, rainbow trout, salmon, eggs, milk, cheese, yogurt,
chicken and turkey. Fortified breakfast cereals are a source of vitamin B12 for vegetarians.
WHAT B12 SUPPLEMENTS ARE BEST?
The food form of B12 is cyano-cobalamin. If you have no genetic defects, digestive problems, or other special needs,
then cyano-cobalamin is adequate for most people. But many people with deficiencies have defects in digestion,
absorption or metabolism, and they need the pre-metabolized form of B12, which is methyl-cobalamin. They also
often need a sub-lingual lozenge, or injections, or other novel forms – such as the new metered nasal spray.
(See below)
HOW MUCH VITAMIN B12 DO YOU NEED?
The RDA for vitamin B12 is about 3 mcg / day of cyano-cobalamin. This is sufficient for a young person about age
20 in perfect health to prevent frank deficiency disease. It is not, however, enough for optimal health, nor
for people with special needs. Most adults with B12 problems need 500 mcg to 1 mg / day. Children need
roportionally less, based on weight and condition.
CAN VITAMIN B12 BE TOXIC? NO.
The Institute of Medicine of the National Academy of Sciences did not establish a Tolerable Upper Intake Level
for this vitamin because Vitamin B12 has a very low potential for toxicity. The Institute of Medicine states that
"no adverse effects have been associated with excess vitamin B12 intake from food and supplements in healthy
individuals". In fact, the Institute recommends that adults over 50 years of age get most of their vitamin B12
from vitamin supplements or fortified food because of the high incidence of impaired absorption of B12 from animal
foods in this age group.
THE NEW METERED NASAL SPRAY
Given the many patients who have special needs for vitamin B12 due to digestion, absorption or metabolism problems,
there is a new vitamin B12 therapy available. This is a custom compounded methyl-cobalamin (pre-metabolized form)
available in metered nasal spray. It is available through licensed health care providers, but is not a prescription,
and therefore can be ordered by licensed nutritionists. It is available for children and adults to replace
injections -- which children hate. It is $90 for a 30 oz metered nasal spray, containing 60 doses of 1/2 oz spray
of 1000 mcg of methyl-B12. Smaller doses are available for children for about $60. This can be compounded by
certain compounding pharmacies. Dose is usually twice a week for 30 weeks (7.5 months). Contact Dr. Power for more
details.
MORE INFORMATION
For more information and references on vitamin B12, see the National Institutes of Health web site:
http://ods.od.nih.gov/factsheets/vitaminb12.asp
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