Vitamin B12

Cobalamin, Dibencozide

Vitamin B12 and its deficiency syndrome, pernicious anaemia, was recognised and described as early as 1855. Vitamin B12 is a bright red crystalline compound because of its high content of cobalt. Vitamin B12 works with folic acid in many processes, including the synthesis of DNA, red blood cells, and the myelin sheath (surrounding nerve cells). Dibencozide is the coenzyme form of vitamin B12.

ANXIETY / DEPRESSION - nervousness and anxiety may be associated with vitamin B12 deficiency. Vitamin B12 deficiency can cause depression, especially in the elderly. Vitamin B12 is needed for the production of tetrahydrobiopterin (BH4), an essential coenzyme required for the manufacture of neurotransmitters such as dopamine and serotonin. The supplementation of folic acid and vitamin B12 stimulate the production of BH4.
HYPERHOMOCYSTEINEMIA - approximately 20-40% of patients with heart disease exhibit elevations in homocysteine, a factor known to be responsible in the progression of atherosclerosis and osteoporosis.
DIABETIC NEUROPATHY - vitamin B12 has been used with some success in treating diabetic neuropathy although it is not clear if this because of a correcting of a deficiency state or the normalisation of the deranged vitamin B12 metabolism seen in diabetics.
MALE INFERTILITY - since vitamin B12 is critically involved in cellular replication, a deficiency leads to reduced sperm counts and sperm motility. Even in the absence of vitamin B12 deficiency, supplementation is worthwhile in men with sperm counts less than 20 million per millilitre or a motility rate of less than 50%.
TINNITUS - a significant number of patients with tinnitus or noise-induced hearing loss have been found to have vitamin B12 deficiency. This effect would appear to be due to changes in neurological function within the auditory system.
SLEEP DISORDERS - Interestingly, vitamin B12 also influences melatonin secretion. Low melatonin status may be due to low B12 levels. Vitamin B12 intake of 1.5mg / day has produced good results in the treatment of sleep-wake rhythm disorders, through improved melatonin secretion.

Dosage

A standard dose to treat pernicious anaemia is 2mg (2,000mcg) daily of vitamin B12 for 1 month, followed by a daily intake of 1mg. Due to poor dietary availability, a vitamin B12 supplement is recommended for vegetarians and vegans. No clear toxicity from large doses of vitamin B12 has ever been recorded.

Potential applications

Depression and anxiety, cardiovascular disease (atherosclerosis), diabetic neuropathy, AIDS (10-35% of all patients have low B12 status), Alzheimer's Disease, asthma and sulphite sensitivity, multiple sclerosis, low sperm count, tinnitus, and pernicious anaemia, fatigue, and red blood cell production. Pernicious anaemia - vitamin B12 deficiency, results in impaired nerve function, which can cause numbness, pins-and-needles sensations, or a burning feeling. It can also impair mental function and lead to a demyelinating disorder of the central nervous system.

Known contraindications

None known.

Interactions

A high intake of folic acid may mask a vitamin B12 deficiency. Those using the anti-diabetic drug Metformin should supplement with folic acid and vitamin B12. Oral contraceptive drugs are likely to deplete vitamin B12 amongst other nutrients.

Use in conjunction with

Jet lag - Rhodiola, B complex, pycnogenol/grape seed extract

Note

In order to absorb the small amounts of vitamin B12 found in food, the stomach secretes intrinsic factor, a special digestive secretion that increases the absorption of vitamin B12 in the small intestine.

REFERENCES

Michael Murray. 1996. The Encyclopaedia of Nutritional Supplements. P. 44-53
Bowman and Russell. 2001. Present Knowledge in Nutrition. Eighth Edition.
James L. Groff, Sareen S. Gropper, Sara M. Hunt. 1995. Advanced Nutrition and Human Metabolism. 2nd Edition.Wyatt KM,
Yamazaki J, Sugishita M, Moriya Y, Isojima G, Ohshima H, Yamazaki O, Takeda Y, Yamauchi T, Takashima M, Takahashi K. The effects of vitamin B12 on the suppression of melatonin secretion under illumination. Jpn J Psychiatry Neurol. 1991 Mar;45(1):169-70.
Honma L, et al. Effects of vitamin B12 on plasma melatonin rhythm in humans: Increased light sensitivity phase-advances the circadian clock? Experentia 48, 716-720, 1992

Like this page? Please link to us and let the world know!

^ back to top