Functions

Vitamin B12 is involved in the metabolism of single carbon fragments, synthesis of genetic material, red blood cell formation, nervous tissue metabolism. Related to normal growth.

Uses

Used in anemia; pernicious anemia; anemia of pregnancy (with Fe & folate); macrocytic anemia (w/folate) allergies; asthma; contact dermatitis; atopic derm; canker sores; viral hepatitis; herpes zoster; psoriasis;acne in adults; seborrheic derm; diabetic neuropathies; neuralgias; fatigue; bursitis; sciatica; insomnia;depression; degeneration of long nerve tracts in spinal cord.

Deficiency

Deficiency may result in pernicious anemia; noise or light intolerance; achlorhydria; progressive peripheral neuropthy; fatigue; depression; confusion; memory loss; psychosis; glossitis; impaired lymphocyte response; dec phagocytic and PMN response; spinal degeneration; macrocytic cells.

Deficiency may be due to impaired production of intrinsic factor.

Antagonists

B12 is destroyed by large amounts of vit C.

Co-factors

Vitamin B12 has a specific absorption process. It is bound in the stomach by instrinsic factor, a glycoprotein, and is absorbed in the small intestine as a complex.

Cofactor is folate, which vitamin B12 works together with in cell division.

Drug Interactions

Alcohol increases breakdown of the biologically active form of vitamin B6 and long-term use may cause liver damage which interferes with the conversion of vitamin B6 to the active form. Amphetamines, levodopa, some antidepressants, isoniazid, penicillamine and hydralazine may alter vitamin B6 requirements. Oral contraceptives may also affect vitamin B6 metabolism and increase needs. Large doses of vitamin B6 may interfere with the action of anticonvulsant drugs. Should not be taken by patients on L-dopa or Sinemet.

Dose

RDA: 2.4 mcg adult; pregnancy 2.6 mcg, lactation 2.8 mcg

Naturopathic doses often much higher, injectable forms.

Toxicity

None known.

Sources

Vitamin B12 is found in:

• Beef liver
• Salt-water fish
• Oysters
• Brewer's yeast
• Sea vegs
• Liver
• Kidney
• Milk & Dairy foods
• Meat
• Eggs