Elaboration on vitamin B12

Kolber and Houle’s article “Oral vitamin B12: a cost-effective alternative”¹ requires elaboration. As reported, vitamin B12 (VB12) deficiency is prevalent in 5% of Canadian adults brought on by medications, diet, macrocytosis, peripheral neuropathy or atypical neurologic symptoms, and dementia. Successful treatment is acheived by raising VB12 serum levels to between 140 and 700 pmol/L. An initial VB12 intramuscular boost followed by an oral VB12 dose of 1000 μg daily is invariably sufficient. Consequently, there should be little need for continuing parenteral VB12.²

Unfortunately, there are some patients, free from the above ailments, with normal serum levels who benefit from parenteral VB12. With intramuscular injections, VB12 serum levels well above 700 pmol/L are reached. These patients report suffering from fatigue or “lack of energy” and state that the intramuscular VB12 gives them “increased energy.” It cannot be entirely an injection-placebo effect because I have not seen this response from a fatigued patient who has been given any other type of injection to treat his or her ailment.

Perhaps VB12 has a binary effect. Serum levels between 140 and 700 pmol/L are required to treat the primary physiological conditions mentioned above. However, a much higher serum level—perhaps 800 pmol/L—might be required to treat the psychological (fatigue) component, and this serum level can only be obtained rapidly by parenteral VB12. For example, polymyalgia rheumatica can be treated successfully with 15 to 20 mg of prednisone; however, the frequently accompanying condition of temporal arteritis (giant cell arteritis) requires 60 mg of prednisone for effective treatment.³

In 2009, Hsia and Howson-Jan, who researched VB12, answered the question of whether high-dose oral VB12 can replace injected VB12 as follows: The short answer is no .... It is also interesting to note that many patients report increased energy after parenteral B12 administration, even in the absence of B12 deficiency. I have not yet noted very many patients reporting this with oral B12 replacement.⁴

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