Vitamin B12 Recommendations
I have changed my vitamin B12 recommendations.
A 2010 paper by Bor et al., showed that in healthy people aged 18-50, a vitamin B12 intake of 4 to 7 mcg/day was associated with the lowest methylmalonic acid and homocysteine levels (1). They reviewed other research from the past 10 years, primarily on older populations, that reinforces this finding.
My previous recommendations were 1.5 – 2.5 µg twice per day. I have changed that to 2.0 to 3.5 µg twice per day. For supplements, I raised the lower end of the range from 10 µg to 25 µg. The daily range is now 25 to 100 µg.
You can read an explanation of my recommendations here under Step 2.
1. Bor MV, von Castel-Roberts KM, Kauwell GP, Stabler SP, Allen RH, Maneval DR, Bailey LB, Nexo E. Daily intake of 4 to 7 microg dietary vitamin B-12 is associated with steady concentrations of vitamin B-12-related biomarkers in a healthy young population. Am J Clin Nutr. 2010 Mar;91(3):571-7.
March 6th, 2010 at 3:26 pm
Do you see any danger in excessive B-12 levels? I’ve been taking 1,000 mcg once a day and eating fortified foods.
March 6th, 2010 at 7:30 pm
Once in awhile I hear from someone who has had an acute reaction to large doses of vitamin B12. It’s not clear to me whether it’s the B12 or something else in the pill that is causing the reaction. As far as long-term problems are concerned, none have been established. That said, there is no need to take so much, unless you have B12 absorption problems.
March 12th, 2010 at 4:16 am
“As far as long-term problems are concerned, none have been established.”
Does that mean: several studies find no problems with sustained high B12 intake? Or: not many studies have been done on that?
I’m asking since I take a daily multivitamin that contains 15 µg B12 but in addition a biweekly standalone 1mg B12 pill as a “precautionary boost”. I’m thinking of cutting out the biweekly.
March 12th, 2010 at 9:41 am
Is it fine to take 1000 mcg B12 supplement pills once a week?
Thanks !
March 12th, 2010 at 10:43 am
> Does that mean: several studies find no problems with sustained high B12 intake?
No, it would be impractical to study such a thing as you would need tens of thousands of people with sustained high B12 intake for many years.
Most of the B12 in a supplement of 1,000 µg will not be absorbed but will be excreted out by way of the digestive tract. Is it possible that this much B12 could be a problem in the intestinal tract? Possibly, but, in my opinion, unlikely. People taking 1,000 µg multiple times a week are likely to absorb more B12 than the average person. If we look at people who absorb more B12 on a long term basis, the research I can think of that would relate to this shows that lower homocysteine levels, a manifestation of higher B12 absorption, are linked with lower rates of mortality, heart disease and stroke.
But, really, the best that can be said is that no one has noticed any problems with taking that much. There are no short term effects and no good reason to think that there would be any long term effects.
March 12th, 2010 at 10:46 am
I think it’s fine to take them 2 or 3 times a week. Or possibly even every single day. But 2 times a week should be enough to maximize your B12 status, so there is no need to take more if you are concerned that it could be a problem.
March 13th, 2010 at 10:34 pm
Hey Jack -
I found this company at the natural product expo in anaheim this weekend. they have this really cool product – a b12 lollipop. Can you check it out and tell me your thoughts on this?
http://www.revitapop.com/
March 14th, 2010 at 12:41 pm
What are your B12 daily and/or weekly recomendations (for supplements in pill form) for vegan and vegetarian children, 1 year and up? What is the safe amount?
March 14th, 2010 at 7:48 pm
Have you any thoughts on the effectiveness of B12 patches? I’ve been thinking of trying them.
March 15th, 2010 at 10:04 am
Methylcobalamin is one of the two forms of B12 that are used by the body in the chemical reactions that require vitamin B12. The other one is adenosylcobalamin. The form of B12 found in most supplements is cyanocobalamin, which is a more stable form and thought to be more readily absorbed. Some people think it’s better to get methylcobalamin because it’s one of the forms the body uses, but all the cells of the body should be able to convert cyano- to methyl- and adenosyl-.
That said, I don’t see any harm in this B12 lollipop, but I don’t think it’s necessary either.
March 15th, 2010 at 10:10 am
Ales,
Cutting the dose in half for for pre-teens should work fine. Teenagers can have the same recommendations as adults.
Jack
March 15th, 2010 at 10:12 am
Caela,
Since supplements work well, I haven’t taken the time to research B12 patches.
March 18th, 2010 at 9:08 pm
But what is the significance of these “biomarkers”? I eat fortified foods regularly, but probably not on a daily basis, and probably not close to the recommended value. What will happen to me if I don’t take a supplement? I am 19 and I have only been vegan for two years.
I read somewhere, and I thought it was here, that there is some evidence to suggest that healthy people need hardly any B12 because it can be stored and used in the body for very long periods of time. And that usually severe B12 deficiency in developed countries is caused by nondietary problems (I might be confusing it with another nutrient though).
Sorry, I don’t know where else to ask these questions…
March 19th, 2010 at 8:38 am
Amanda,
The main worry is that you might develop high levels of homocysteine which, over many years, could cause an increased risk of heart disease, stroke, dementia, and early death.
> I read somewhere, and I thought it was here, that there is some evidence to suggest that healthy people need hardly any B12 because it can be stored and used in the body for very long periods of time.
You definitely didn’t read that here! We’ve known for 10 years now that the body does not store enough vitamin B12 to keep homocysteine levels in check for more than short periods of time.
You might want to check out this page:
veganhealth.org/articles/vitaminb12
If you are not eating fortified foods in the amounts I’ve recommended, then you should probably opt for one of the two supplement options. They are not hard to do.
March 28th, 2010 at 5:49 pm
Do you know if the recommended daily value on fortified foods, such as Silk soymilk, is the one you are recommending, or is it lower?
March 28th, 2010 at 5:57 pm
Amanda,
The Daily Value on fortified foods is based on 6 µg.
May 5th, 2010 at 7:09 pm
What about just eating brewer’s yeast or nutritional yeast and skipping the pills?
May 7th, 2010 at 1:59 pm
Leslie,
Eating fortified foods is fine and is mostly how I get vitamin B12 (I take a 1,000 µg pill once in awhile). But brewer’s and nutritional yeast do not have vitamin B12 unless they are fortified with it. You also have to take care not to let them sit out in the light as that can damage B12.
July 1st, 2010 at 10:58 am
I totally agree with increasing the recommended intake of B12, based on my personal experience as well as the recent research findings. I developed a B12 deficiency despite taking a supplement containing 10mcg every day since I gave up meat. I had tests done which showed that my absorption of B12 is normal, so the deficiency was caused by inadequate intake rather than poor absorption. Given how serious B12 deficiency can be, nobody should be taking the risk of inadequate intake.
August 24th, 2011 at 11:03 am
Hello, sorry to spam an old post, I didn’t know who else could answer my question…
I was wondering what you think about the Vegan Society multivitamin, Veg-1… I’ve never seen it mentioned in your different recommandations and just noticed that it contains only 10µg of B12. Which, according to you and the unfortunate person preceding my comment, is not enough.
I’ve been thinking of taking two pills daily instead of just one, but I don’t want the rest to become a problem because of an excessive intake (vitamins B2 (1.6mg), B6 (2mg), D (10µg), iodine (150µg), selenium (60µg) and folic acid (200µg)). Should I keep taking this one and another B12 supplement? Or maybe another multivitamin would be better?
We have no fortified food in France and vegan supplements are not easy to find, that’s why I’m taking this one… (silly anti-vegan politics).
August 24th, 2011 at 12:29 pm
Caroline,
> it contains only 10µg of B12. Which, according to you and the unfortunate person preceding my comment, is not enough.
There is a difference between “enough” and “ideal.” 10 µg should be enough to prevent any sort of overt B12 deficiency and keep homocysteine levels relatively low. I would not take 2 per day.
October 13th, 2011 at 3:29 pm
Hi Jack,
I just purchased some Nature’s Bounty Sublingual B12 tablets – they are 2500 mcg each and the label says to take one a day – that seems excessive based on what has been posted here… I was thinking about doing one once a week for me and a half of a tablet once a week for my 6-year-old son.
We both also take a multivitamin daily that has 6 µg B12.
Does this seem like a reasonable plan?
Thanks!
October 13th, 2011 at 4:14 pm
Tamara,
I would cut the pill in half and take one half two times a week for you, and cut it in quarters and have your son take one quarter two times a week. I am basing this on my chart here:
http://veganhealth.org/articles/dailyrecs
October 17th, 2011 at 3:26 pm
Thanks! That makes sense, I was just doubting my math or something since the bottle says to take a whole one every day!
November 21st, 2011 at 5:38 pm
I am a little puzzled at the B12 recommendations you list in the table at http://veganhealth.org/b12/rec
If I’m reading that table correctly, adults should get 2.4 ug based on the US RDA, but the recommendation is 25ug – 100ug per day.
However, where it gets confusing is it also lists 2 – 3.5ug as the “2 Doses per Day” recommendation. That’s 2x the US RDA, but only a tiny fraction of the recommended daily dose. Why? And why is the recommended 2x weekly dose of 1000ug 10x the maximum recommended daily dose?
I understand that some people may prefer to take their B12 once per day, or twice per day, or twice per week, but shouldn’t the doses all add up to the same amount per week? That is, if the recommended daily dose was 100ug, shouldn’t the recommended weekly dose be 700ug, not 2000ug?” (Based on the maximum daily recommendation of 100ug)
November 21st, 2011 at 5:58 pm
puzzled,
I list the US RDA in that table simply as an fyi. The reason I do not simply suggest that vegans meet the US RDA is because:
1. The RDA is based on what intake of vitamin B12 will prevent macrocytic anemia, rather than what amount will lower homocysteine and methylmalonic acid to optimal levels. My recommendations should accomplish all of these things.
2. The RDA is intended for people who are eating B12 multiple times a day as most omnivores do.
When you are getting your vitamin B12 in 2 doses or less per day, the amount of vitamin B12 that can be absorbed at one time becomes an issue. The are 2 ways to absorb B12: via transport proteins (called intrinsic factor) and by diffusion. The intrinsic factor route becomes saturated at about 1 to 1.5 µg per day. Anything above that ingested at the same time will only be absorbed at a rate of about 1 to 1.5%. So, as the frequency of taking B12 goes down, the amount rises rather steeply.
I explain all of this in a lot more detail in How Recommendations Were Formulated of Vitamin B12: Are You Getting It?
January 27th, 2012 at 3:10 pm
This might be a silly question, but going by the recommended values, what would be the best way to proportion a 500 mcg B12 supplement? Can I just take two twice a week to meet the ~1000 mcg recommendation? Or take one every other day? This is for a vegan diet and having no known B12 deficiency.
January 27th, 2012 at 3:14 pm
Nick,
Not silly. But the answer is to combine them to make a 1,000 mcg tablet and take 1,000 mcg twice a week. You’ll actually absorb more if you take 4 by 500 mcg per week at different times, but that isn’t necessary.