Methylcobalamin & Adenosylcobalamin: Consolidated

It’s raining B12!

I have consolidated all the information from my blog and regarding the benefits and drawbacks of supplementing with the co-enzyme forms, methylcobalamin and adenosylcobalamin, over cyanocobalamin.

Click here: Methylcobalamin & Adenosylcobalamin


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6 Responses to “Methylcobalamin & Adenosylcobalamin: Consolidated”

  1. Tom Walsh Says:

    Hi Jack, I’ve just seen this article and wondered if I should be taking a Glutathione supplement along with B12 (Cyanocobalamin).

  2. Jack Norris RD Says:


    > wondered if I should be taking a Glutathione supplement along with B12 (Cyanocobalamin).

    No need to take a glutathione supplement along with cyanocobalamin.

  3. Dima Says:

    Hi Jack,

    I’ve been looking through scientific literature to figure out how often veg*ns should do cyanocobalamin injections and what dosage should be used. So I needed to know what percentage of the vitamin administered intramuscularly gets absorbed and how long it stays in the body.

    What I have found is quite controversial.

    “The bioavailability of the cobalamin injection is assumed to be 100%”

    “adequate maintenance treatment of uncomplicated vitamin-B12 deficiency states will be achieved by parenteral administration of 1000 mcg cyanocobalamin every 2 months”

    “about 20 per cent CN-B12 being retained after the injection of approx. 1 mg”

    half-life: 6 days in serum, 400 days in liver

    Can you shed some light?

    Also it would be great to see IV B12 recommendations on

    Best wishes.

  4. Jack Norris RD Says:

    Hi Dima–

    I know very little about IV B12 and I don’t really consider it a vegan issue. I would recommend people discuss this with their health professional.

  5. Dima Says:

    Thank you, Jack! I made a typo. I didn’t mean intravenous administration. My question is about intramuscular one, the cheapest and most convenient way to get the vitamin.

  6. Jack Norris RD Says:

    Hi Dima–

    I understood you as meaning as injections rather than oral, so it doesn’t change my views on it which is that I don’t have the inclination to get involved in researching and making recommendations for it.

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