I know you work hard to make the best lifestyle choices
so you can improve your health, destiny, and longevity.
And there’s lots of information out there on how to do just that.
So where do you start? Well – we start with the facts.
Welcome to the Nutrition Facts Podcast – I’m your host Dr. Michael Greger.
My job is to bring you the latest peer- reviewed nutrition and health research
and share it with you here.
Today on the show – the mighty Vitamin B-12.
Did you know B-12 is an essential nutrient
that your body can’t make useably on its own,
so you need to get it from your diet or supplements.
Today we start with the best green-light sources of B-12.
A regular, reliable source of vitamin B12 is critical for anyone eating
a plant-based diet, either vitamin B12 supplements
or vitamin B12 fortified foods.
I've talked about my B12 supplement recommendations,
either 50 micrograms a day, or once a week doses of 2,000 micrograms.
I think that's the simplest, cheapest way: taking it once a week.
That's how I do it. But if you don't want to take supplements,
you'd have to rely on B12-fortified foods, in which case you'd have
to eat three separate servings of B12-fortified foods,
each ideally containing at least 190% of the so-called "Daily Value"
on the product's nutrition facts label. How does that make any sense?
And what's the term "Daily Value" even mean? The term Daily Value
is used to designate both the DRV, Daily Reference Values,
and RDI, Reference Daily Intakes, that are based on the
Recommended Daily Allowances, all to limit consumer confusion.
See, aren't you less confused now?
Anyway, the daily value of B12 was set at 6, which was recently changed
to 2.4 in 2020, making it all the more confusing,
and so 190% of 2.4 is about 4.5.
Plug that into the equation I detailed in the last video
and you get about 1.16 absorbed from each serving,
times three times a day, and poof: there's your 3.5 for the day.
OK, so how much like nutritional yeast would that be,
a commonly B12-fortified food source? It depends on the brand.
Going alphabetically, Bob's Red Mill brand has 730% per quarter cup,
so you'd only need about 4 times less than that to make up a serving,
so around one tablespoon. So one tablespoon of this brand
sprinkled on each meal and your B12 would be taken care of.
Bragg's says it's even more potent at 563% per tablespoon;
so just a teaspoon three times a day should suffice.
Dr. Fuhrman's brand is explicitly unfortified, and so contains zero B12,
so that's an important lesson. You can't just assume nutritional yeast has B12.
So if you find it in the bulk section; I mean you have no idea
what it contains unless you actually see the package.
Same with the Frontier Co-op brand: zero vitamin B12.
KAL brand has 500% of the Daily Value of B12 per three rounded tablespoons,
so one rounded tablespoon should suffice as one of the servings.
NOW brand has more, with two teaspoons sufficing.
Red Star has 333% per one-and-a-half heaping tablespoons,
so a serving would be like one tablespoon,
but note only some of Red Star's nutritional yeast varieties
have any B12 at all. So just remember to check the label.
And finally, Trader Joe's looks like 1.5 tablespoons could count as one serving.
So it looks like Bragg's is the most potent currently available.
There are all sorts of other B12 fortified foods from plant-based
meats and milks to breakfast cereals and energy drinks,
but are there any other green light sources, meaning plant foods from
which nothing bad has been added and nothing good has been taken away?
What about various algae-type products like spirulina,
which are advertised as natural vitamin B12 sources?
Not only do they not actually contain B12 that's useable for humans,
it's even worse than that. They may contain B12 analogues,
look-alike molecules that can even block your absorption of real B12.
I was excited to see that there was an herbal tea with B12,
but so little you'd have to quadruple bag it.
If you didn't want to take a pill, which again I think is really the best way,
the easiest option would probably be LeafSide foods.
I've always loved them because they center their ingredients
around my Daily Dozen. Unfortunately, people see them citing my science
and think I have some sort of financial relationship, but of course I have
no financial ties to any food company, drug company, supplements, kitchen
gadgets, and no personal financial ties with any commercial entity whatsoever, ever.
I'm happy to voluntarily plug LeafSide though, as their food has kept me
from starving on the road on many occasion. They're freeze-dried,
so they're light and easy to travel with, and I just use my hotel room
coffee maker to make hot water and poof.
But anyway, each of their meals has 75 mcg of B12. So one a day
and you'd get all your B12 without having to take a supplement,
but it's only 100% green light if you specify you want the salt-free versions.
They have no added salt/fat/sugar versions of all their products
at no extra cost, but you have to specify that when you order.
In our next story we look at the optimal vitamin B-12 dosage
for kids, pregnant women and seniors.
Universal improvement of B12 status appears “to be a nutritional
imperative with possibly profound beneficial effects,”
particularly at the bookends of life—at old age and infancy.
I’ve explained the rationale for my recommendations
to take vitamin B12 supplements once a week or once a day,
or alternately eat sufficient daily B12-fortified foods.
But for those over age 65 those guidelines go out the window.
The recommendations change to everyone taking
a high daily dose of 1,000 mcg every day.
Starting at age 50 everyone, meat-eaters and vegans alike,
should be taking B12 supplements or eating B12-fortified foods.
But over age 65, 50 a day may not do it. Even 100 a day doesn’t seem sufficient.
Researchers investigated three doses and found that most
didn’t normalize their MMA until after the 1,000 microgram dose.
(MMA suppression is a measure of B12 sufficiency.)
But they just tested 25, 100, and 1,000. Maybe 250 or 500 would do it?
Researchers set out to find an adequate dose at that age,
and it seems we need at least about 650 to 1,000 a day in most people,
hence my 1,000 a day recommendation after age 65.
OK, what about the other end of the life cycle?
The consequences of B12 deficiency and insufficiency can be
devastating in infancy and childhood,
and this is not just a problem for plant-based pregnancies.
“Vitamin B-12 insufﬁciency during pregnancy is common
even in nonvegetarian populations.”
About a quarter of all pregnant women aren’t getting enough B12,
and that number rises to nearly one in three by the third trimester.
But, insufficiency isn’t as bad as frank deficiency,
which can manifest in cases like cerebral atrophy,
meaning brain shrinkage,
in a “Vitamin B12-deficient Infant of a Vegetarian Mother.”
Thankfully, even severe brain atrophy can be
substantially reversed with B12 supplementation,
but better not to become deficient in the first place.
The solution proposed by a group of French pediatricians
is to recommend against raising vegan kids at all,
since B12 supplementation is necessary. And they’re not alone.
To vegan or not to vegan.
In 2016, two professional organizations, the U.S. Academy
of Nutrition and Dietetics and the German Nutrition Society,
issued conﬂicting statements.
The U.S. Academy said that even strictly plant-based diets
are appropriate for all stages of the life cycle,
whereas the German group echoed the French group,
saying since you have to take B12 we can’t recommend a vegan diet
for pregnant women, lactating women, infants, children, or adolescents.
To confuse the matter further, the American Academy of Pediatrics
appeared to have it both ways; in one place repeating
the U.S. Academy’s position, while in another place it stated that
vegan diets should not be recommended for children.
But I think they’re just saying the same thing.
Everyone agrees that a non-B12 supplemented plant-based diet
is a bad idea—that’s part of what the U.S. Academy means
by “well-planned.”
Everyone eating plant-based, but especially pregnant
and breastfeeding women, must ensure a regular, reliable source
of vitamin B12, meaning B12 supplements or B12-fortified foods.
But then you may be able to get the best of both worlds.
That’s why there are reviews with titles like this:
plant-based pregnancies: danger or panacea?
Danger if you don’t take your B12, but “following a plant-[based] diet
during pregnancy may be protective against the development of preeclampsia,
pre-gravid obesity, and minimize the exposure to [DNA-damaging] agents.”
It may also protect our newborns “from the onset of pediatric diseases,
such as pediatric wheezing, diabetes, neural tube defects,
orofacial clefts, and some pediatric tumors.”
“Vegan pregnant women have a lower-than-average
rate of cesarean section, less postpartum depression,
and lower neonatal and maternal mortality,
with no complications or negative outcomes that are higher than average.”
In addition, a lower incidence of what used to be called toxemia,
a potentially dangerous pregnancy complication known as preeclampsia.
“Overall, plant-based diets seem to confer protection to both
mothers and newborns” by not only “reducing the risk of several
pregnancy-related issues”, but decreasing the risk of childhood disease.
“Children following plant-based diets might have a lower risk
of developing obesity,” obviously are less exposed to drugs
used in animal production, and a favorable
anti-inﬂammatory proﬁle of cell-signaling factors.
But again, everyone on a plant-based diet has to get enough B12.
Pregnant and breastfeeding women can just follow
my 50 micrograms a day recommendation for nonpregnant adults,
or 2,000 a week, though they suggest breaking up those doses
into two halves to boost absorption.
After infants are weaned, they can start on 5 micrograms a day;
from ages 4 through 10 they can take half the adult dose of 25 a day;
and then at age 11 they can take 50 a day or 2,000 a week.
You don’t have to worry about taking too much.
It’s water-soluble and you’ll just end up with expensive pee.
In our last story about Vitamin B-12 –
we’ve got one word for you – cyanocobalamin.
Say that five times fast.
I've talked about the optimal dose of vitamin B12 supplements for adults,
as well as in childhood, pregnancy, and old age to prevent
vitamin B12 deficiency. But what if you already have it?
How much do you have to take to treat it?
Your doctor might want you to get vitamin B12 injections,
but oral B12, even for those who can't absorb it well,
has long been considered one of medicine's best kept secrets.
It's now considered well-known that orally administered B12 supplements
are as effective in overcoming deficiency states as intramuscular injections
when you get up to taking 1,000 micrograms a day.
How long do you have to take 1,000 a day for?
It depends on how low your levels start out.
Because B12 status in pregnancy is so critical,
there is a suggestion that plant-based women get it checked
throughout pregnancy and to adjust supplementation as necessary.
Note the recommendations for pregnant and breast-feeding women
are the same as everyone else over the age of 10.
So if you're a teen or adult diagnosed with vitamin B12 deficiency,
you'd take 1,000 micrograms a day for one to four months,
depending on how low you start out, before going back
to a regular maintenance dose of 50 a day or 2,000 a week,
with toddlers and small children taking smaller doses.
There are two main types on the market though: methylcobalamin,
marketed as methyl B12, and cyanocobalamin,
typically marketed as just vitamin B12.
Methyl is more expensive so it must be better, right?
Wrong. Cyanocobalamin is the most used form due to its high stability.
See, methylcobalamin is less stable than cyanocobalamin,
and it is particularly susceptible to photodecomposition,
meaning destruction from being exposed to light.
There's no advantage to using the light-sensitive forms of cobalamin,
such as methyl B12, instead of the stable cyano forms, which are readily
converted in the body into the type you need, where you need it.
The one major exception may be kidney failure though.
Methylcobalamin may be better for those with impaired kidney function.
It's been speculated that oral methylcobalamin or injected
hydroxycobalamin may also be preferable in smokers,
though it has yet to be confirmed.
Because methylcobalamin is less stable, you'd probably want to take
much higher doses. So for example, in those with kidney failure, you'd be
taking one to two thousand micrograms a day, compared to just 50 micrograms
of cyanocobalamin in someone with normal kidney function.
Another reason to use the cyanocobalamin, as opposed to
the more expensive kinds, is that it has a track record of safety and efficacy,
whereas, for example, in one study even up to 2,000 micrograms a day
of methylcobalamin wasn't enough to correct vitamin B12 deficiency
in one of three vegans they tested it on.
The bottom line is that so-called coenzyme forms of B12,
like methyl B12 and adenyl B12, also known as adenosyl B12,
are not likely to be superior to cyanocobalamin, which is more stable.
Cyanocobalamin appears to be best suited for oral supplementation,
which is why I specify its use in my recommendations.
Note I also recommend ideally taking it separately
as a chewable, sublingual, or liquid supplement.
Why can't you just get it as part of a multivitamin or something?
Because various vitamins and minerals mixed into the same pill
can destroy active B12, forming B12 analogues—B12-look-alikes that (not)
only can our body not use, the analogues can be potentially harmful
because they can inhibit the transport of what little B12 is left.
That's why using multivitamins can even be counterproductive
for the supplementation of vitamin B12. And this isn't just in theory.
There was a tragic case of severe vitamin B12 deficiency in an infant
born to a vegan mother who thought she was doing everything right
taking a multivitamin that contained B12,
though it may have also just been inadequate dose.
Why chewable or sublingual?
Absorption is boosted when the B12 mixes with saliva,
since you secrete a B12 binding protein from your salivary glands
that helps transport B12 safely through the digestive tract.
Having people chew a tablet of B12 and their B12 levels go up 10 times more
than just simply swallowing the exact same pill. Check it out.
Vegans boosted out of deficiency chewing a B12 supplement,
but nothing in those who just swallowed it whole.
Maybe they had some sort of absorption problem or something?
No, because then if you tell them to start chewing it instead
of swallowing it whole, their levels shoot right up as well.
In my latest book How Not to Diet, I suggest a third option to B12-
fortified foods and supplements: brushing twice daily with
a B12-fortified toothpaste, specifically this brand,
which was put to the test in two double-blind,
randomized, placebo-controlled studies.
Participants were instructed to use the toothpaste two times a day
for two minutes at a time, and indeed, were able to correct the markers
of B12 insufficiency in the blood of vegans and among the elderly,
but that was on average. Unfortunately, it didn't work in every last person,
which is why it's not included in my recommendations.
Though, look, if you get your levels tested before and after brushing
for a few months and they go up, then you could presumably stick with it.
In summary, vitamin B12 deficiency is not to be messed around with,
with the potential to cause a wide range of disorders of the gut,
blood, brain, and nervous system.
With the ever-increasing demand for cleanliness in our food chain—
which is a very good thing—
it is of special importance that we secure a regular reliable source,
and the safest, cheapest, healthiest source is B12 supplements
or green-light B12-fortified foods.
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