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Forums: Main Kickstart Forum: B12 suppliments
Created on: 01/06/13 06:30 PM Views: 2180 Replies: 6
B12 suppliments
Posted Sunday, January 6, 2013 at 6:30 PM

i wasn't sure if it was necessary to take a B12 supplement so early on into being vegan, but i thought better safe than sorry.
There is a bit of conflicting information about the dosage levels and the type of B12.

When i started this i got a 1000mcg tablet that you swallow from the supermarket. The B12 is derived from cyancobalamin.
And based on what i read in The Starch Solution i got the impression that it would be fine to just take this once a week due to it's high dosage.

But then i heard that no, for 1000mcg i should be actually taking it twice a week because the body requires more when the dose is less frequent.

And then i read tablet you swallow can't be easily absorbed...
And then that cyanobalmin is bad, possibly even toxic and that i should be taking sublingual methylcobalamin.
That is a lot more expensive and i'd have to order it online rather than getting it in a grocery store like the one i got.

Any thoughts? Is this overkill only 1 week into being vegan? Can i at least finish off the bottle i originally bought and should i be taking it once or twice a week?


Note- my soy milk also has some B12 in it, but i'm not drinking alot. Maybe 1 cup a day at most. Also i'm waiting on some nutritional yeast to come in the mail but probably won't be able to afford to have a tbs a day as is recommended to cover the B12 requirements. I don't eat fake meats so don't have a B12 source there.

RE: B12 suppliments
Posted Sunday, January 6, 2013 at 7:03 PM

Hey Dirtbooksun!

Here is an article and video by Dr. McDougall that you may find helpful:

Do you need to supplement vitamin b12 on a plant-based diet?


Lani Muelrath, M.A. CGFI, CPBN
Fit Quickies: The Plant-Based Fitness Book

RE: B12 suppliments
Posted Sunday, January 6, 2013 at 7:16 PM

Thanks for that.

But that is what i mean about contradicting info. Those two doctors have slightly different recommendations.

McDougall says 500mcg or more per week is enough.
Reed Mangels says 2000 mcg.

McDougall recommends hydroxy or methyl forms whereas Reed Mangels doesn't specify although mentions multivitamins and cereals. And most multivitamins and cerials would have the cyanocbalmin form because it is much cheaper.

So is it just the form that accounts for the different dosage recommendations? So if you are using cyanocobalamin take 2000mc per week but not as much will be needed if using Methylcobalamin?

Sorry i've getting really technical here. I just like to be through and make sure i'm doing the right thing.

Right now i'm leaning towards taking 2000mcg per week until my bottle of cheap supermarket B12 runs out and then look for a higher quality more expensive Methylcobalamin one to replace it afterwards.

RE: B12 suppliments
Posted Sunday, January 6, 2013 at 9:55 PM

It may indeed have something to do with the source. I'm betting Susan will come in Monday and share her wonderful expertise on the subject!


Lani Muelrath, M.A. CGFI, CPBN
Fit Quickies: The Plant-Based Fitness Book

RE: B12 suppliments
Posted Monday, January 7, 2013 at 12:29 AM

dirtbooksun, thanks for posting. I've had the same questions as well. It seems there is a lot of conflicting information. For now I've decided to buy chewable tablets of methyl that are 1000mcg. My plan was to take one weekly and to give my 3.5 year old half a tablet weekly. I'm hoping that should be enough in addition to nutrional yeast once in awhile and what is in the cereal we eat.

RE: B12 suppliments
Posted Monday, January 7, 2013 at 10:44 AM

We do tend to store B12 for quite some time, so when first embarking upon a vegan diet, there is no need to be overly concerned. However, I do think that it is important to not only hang onto these stores, but to keep B12 circulating in the body as well.

The amount we need per day is so small, 2.4 micrograms. As you have noticed, most supplements have far more than this, and that's okay, because there is no "upper limit" as determined by health experts.

Because we tend to absorb less as we age, those same experts recommend supplementing with more than 2.4 mcg per day to ensure that enough gets through the gut wall (for anyone, regardless of dietary choices). How much gets through is individualized. I would suggest taking any amount you mentioned two to three times per week and consider supplemented foods (plant milks, grains, yeast, etc.) as bonus. The next time you do a regular blood test at your doctor's office, you can ask her/him to check your B12 status (stores and circulating) to make sure everything is good. If the numbers are too low, take the supplements more often. If they are excessive, you could consider scaling back on the micrograms if for no other reason than to save money, although I know of no reason for concern. If you have been supplementing regularly and the numbers are REALLY low, you may be better off taking a sublingual B12 (bypassing the gut all together).

As for methyl- vs. cyano- cobalamin, there is no evidence that one is better or worse than the other, in terms of manifesting into a health problem. If one can afford to "upgrade" to the more expensive methyl, I would certainly understand as the cyano is related to the less than appealing cyanide molecule.

I hope that helps! Let me know if you have any further questions.

Susan Levin, MS, RD
PCRM Director of Nutrition Education

RE: B12 suppliments
Posted Monday, January 7, 2013 at 3:04 PM

Thanks for this information.

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