Vitamin B12 - Cobalamin

Cobalamin is a member of the B complex vitamins. It occurs naturally in animal products including milk and cheese. Vitamin B12 needs calcium to be properly assimilated. Vitamin B12 is known as the 'feel good' vitamin as it ensures the healthy functioning of the nervous system.

The functions of vitamin B12

Vitamin B12 is necessary for:

stimulating RNA synthesis in nerve cells,
strengthening neurotransmitters, and increasing concentration and memory,
myelin formation (the covering around the nerve cells),
protecting arteries in the brain by metabolizing homocysteine,
nervous system health,
growth and development,
the production of red blood cells,
healthy digestive function, and
detoxifying cyanide from foods and tobacco smoke.

The absorption of vitamin B12 is dependent on HCL (hydrochloric acid) in the stomach and the bonding to a substance called intrinsic factor within the small intestine. Intrinsic factor is secreted by cells of the stomach. These cells are also responsible for the secretion of HCL. The insufficiency or lack of intrinsic factor has been found more commonly among those of Scandinavian, English, and Irish descent.

The symptoms and signs of a vitamin B12 deficiency

B12 is often deficient in vegans (strict vegetarians) because the predominant source of B12 is animal products. It is also prevalent among the elderly population.

Deficiencies have been associated with some forms of dementia. The symptoms associated with a B12 deficiency are:

fatigue,
headaches,
shortness of breath,
sore, beefy red, swollen tongue,
digestive disorders, heart and nervous system disturbances such as:
- numbness and tingling of the arms or legs,
- depression,
- mental confusion, and
- memory deficits.

B12 deficiency can mimic Alzheimer's disease.

Food Sources of vitamin B12

Vitamin B12 is found in: brewer's and nutritional yeast, liver, clams, eggs, meats, fish, and dairy products. Some vitamin B12 is available from sea vegetables, such as, dulse, kelp, kombu, and nori.

Therapeutic uses

Therapeutic levels of vitamin B12 are used in diseases and conditions such as AIDS, Alzheimer's disease, senility, compromised cognitive function, asthma, sulfite sensitivity, depression, diabetic neuropathy, multiple sclerosis, tinnitus, and low sperm count.

How much do you need?

For vegetarians, 100 mcg of B12 daily is recommended. Methylcobalamin, the active form of vitamin B12, in sublingual tablets is the preferred form of synthetic vitamin B12. The amounts recommended in deficiency states are 2,000 micrograms daily for 1 month, followed by 1,000 micrograms daily for 3 to 6 months or until the methylmelonic acid levels in the urine are normal. Vitamin B12 needs to be taken in conjunction with vitamins A, C and E and other members of the vitamin B complex.

Special notes

Those with impaired digestive processes or over or under active thyroid may have problems with B12 absorption. Because of this, or if there is a serious B12 deficiency, a separate B12 supplement may be taken in addition to the B complex until the digestive processes and/or thyroid are normalized or the deficiency dealt with. This should be taken at a different time during the day than the B complex. For these people, it may be advisable to take the active form of B12 (methylcobalamin) in a sublingual form. Vitamin B12 injections are another possibility, though research has shown that this is no more effective than oral administration of B12.

A non-diet related vitamin B12 deficiency is indicative of intestinal overgrowth of toxic bacteria (dysbiosis) and a disturbance in the balance of beneficial bacteria in the intestinal tract. This will result in leaky gut if left untreated. Leaky gut allows large protein particles, undigested food particles, and toxins to move through the intestinal walls and find their way into the blood stream where they cause all kinds of problems. This is the starting point of many diseases.

Dysbiosis requires supplementation with the vitamin B complex, vitamin B12, digestive enzymes, and probiotics, such as acidophilus and bifido bacterium. Zinc and glutamine are helpful in healing leaky gut. It is beneficial to use all of these supplements together to address the entire digestive tract. It is also important to keep the diet free of sugar and processed foods.

Sunlight, water, alcohol, and sleeping pills act against vitamin B12.

A time release tablet is recommended for vitamin B12 because it is not well absorbed through the stomach and these time release tablets offers the opportunity for it to be absorbed in the small intestines.

Chronic diarrhea, intestinal parasites and other digestive disorders inhibit the absorption of vitamin B12 and deficiency is particularly common in the elderly.

References

Bland, J. 1996, Contemporary Nutrition. J & B Associates.

Davies, S. and A. Stewart., 1997, Nutritional Medicine. Pan.

Holden, S., Hudson, K., Tilman, J. & D. Wolf, 2003, The Ultimate Guide to Health from Nature. Asrolog Publication.

Pressman, A. and S. Buff, 2000, The Complete Idiot's Guide to Vitamins and Minerals. (2nd Ed.) Alpha Books.

Soothill, R. 1996, The Choice Guide to Vitamins and Minerals. A Choice Book Publication.

Sullivan, K. 2002, Vitamins and Minerals: A Practical Approach to a Health Diet and Safe Supplementation. Harper Collins.