Friday Favorites: The Optimal Vitamin B12 Dosage and Type

At age 50, everyone should start supplementing with B12-fortified foods or supplements regardless of the type of diet they follow. Over age 65, only high-dose daily supplements may suffice. For prevention and treatment of vitamin B12 deficiency, cyanocobalamin in chewable, sublingual, or liquid forms (rather than in a multivitamin) is best under most circumstances.

What about concerns regarding B12 and acne, bone fractures, and cancer? I addressed those in my B12 webinar, and the videos are available for download here or on ( ). I covered a lot: the dosage needed to treat B12 deficiency, how oral is better than injectable, why the cheaper form (cyanocobalamin) is superior to the more expensive form (methylcobalamin), why you can’t just take it in a multivitamin, and why you shouldn’t take it as a pill you swallow (because it needs to mix with that saliva protein).

I mentioned my book, How Not to Diet, which you can find out more about here ( ). You may also be interested in my next book, How to Survive a Pandemic ( ), available in softcover, audiobook (read by me), and e-book form.

New subscribers to our e-newsletter always receive a free gift. Get yours here: .

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Want to get a list of links to all the scientific sources used in this video? Click on Sources Cited at . You’ll also find a transcript and acknowledgements for the video, my blog and speaking tour schedule, and an easy way to search (by translated language even) through our videos spanning more than 2,000 health topics.

Thanks for watching. I hope you’ll join in the evidence-based nutrition revolution!
-Michael Greger, MD FACLM

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Dave McKinnon

  • @markjones2453 says:

    I take b12 complex 50 once at lunch then after dinner along with nutritional yeast at breakfast probably way to much my hair skin and nails have never looked so good lol and my urine is SUPER EXPENSIVE lol

  • @bonniepoole1095 says:

    I’m so glad that Dr. Greger addressed the dose of B12. I was taking 1000 but then thought it might be too much so I cut dowm to 500. I’m 72 years old, so back to 1000!! Thanks!

  • @andanssas says:

    5:37 I heard or read somewhere a while ago that over dosage, besides being discharged in urine, could affect acne production, is this true?
    Thank you for all the detailed information on dosages 🙏

    • @dominicmutzhas6002 says:

      For injections, yes!
      But with oral the amplitude in the blood seems to not be high enough according to Dr greger

  • @andanssas says:

    9:16 I had no idea about the *potential harmful B12 alteration* when mixed with food, vitamin or mineral supplements.
    This means AG1 is doing it wrong! Thank you for this precious fact gem 🙏

  • @saraa4559 says:

    Great information and insight. Those of us with genetically induced methylation issues ( MTHFR being just one of them), the methylated form is a must!

  • @JuliaJulia007 says:

    Age 63. Had B12 checked 3mos ago. Taking 1200mcg cyno per day. No deficiency at the start. All is well 😊 I will, however, chew them from now on. Thx Dr G

  • @KerriEverlasting says:

    1 of 3 vegans they tested it on? And we are supposed to think thats a study? Really? 🙄

  • @NutritionFactsOrg says:

    Subscribe to’s free newsletter! As a thank you for subscribing, receive a handbook on the Anti-Aging Eight, the specific foods or actions that may best help to slow aging or improve longevity, from Dr. Greger’s new book, How Not to Age.

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