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Wednesday, May 5, 2010


How important is vitamin B12?

For years doctors gave patients injections of that red liquid in their hips for low energy.
Patients left the office feeling energized with an increased sense of well being.

The practice has been eschewed by conscientious doctors in more recent decades: no scientific rationale - just a placebo effect. The elixir is red - red placebos work best. In evidence based medicine, B12 deficiency may be due to maladsorption or an autoimmune disorder. Blood levels are only low when less than 211. Other countries, including Japan have set the bar for normalcy higher - 500 or more. This is quite a difference.

B12 does many things in the body -- in conjunction with folic acid. It helps regulate the production of red blood cells and DNA synthesis. It facilitates the synthesis of myelin, the protective covering around nerves, and it likely has many other functions which are enumerated in a variety of published sources.

Lower B12 levels, less than 500 have been associated with a variety of neuro-psychiatric disorders, inclusive of cognitive dysfunction. B12 supplementation has helped with neuropathies of various sorts despite normal blood levels according to American standards. Neurologists who discount Lyme as a possible cause of peripheral neuropathy readily recommend generous supplementation with B vitamins.

Commercially, B12 is available as cyanocobalamin, an inactive form. It must be converted into one of two active forms, including methylcobalamine. Many clinicians feel that that the expensive methylcobalamine is the only clinically effective form of the vitamin. Based on my survey of the literature the jury is out on this one.

Patients with neuropathy, cognitive issues and perhaps many other issues may benefit from supplementation. Most of my patients have B12 levels which average around 350. This water soluble vitamin has no toxicity. B12 must be given with folic acid. If oral supplementation is ineffective the old "placebo" (B12 shots) can't hurt.