Vitamin B12 supplementation is crucial for anyone eating a plant-based diet,
but does it have any side effects?
Watch the video to find out.
"Do Vitamin B12 Supplements Cause Acne, Bone Fractures, and Lung Cancer?"
Acne is a disease unique to humans. Why do humans get acne?
Well, think about the distribution of those greasy sebaceous glands—face, chest and back—
exactly the same structures that pose the greatest
obstruction during childbirth. So hey, maybe having a little
extra lubrication at those sites would help make the baby
more slippery for birth, conferring a selective advantage
for successful delivery. OK, but what triggers them
to become inflamed into zits later on? While in westernized societies, acne
is a nearly universal skin disease afflicting up to 95% of teens,
in some populations eating more traditional diets not even
single cases could be found. This suggests that perhaps
nutrition counseling should be a first-line therapy for individuals
with mild to moderate acne. It looks like it's the high glycemic
foods and dairy products. So we're talking sugar, soda,
refined junky carbs, white flour, breakfast cereal, and dairy products
like milk, cheese, yogurt, whey, as well as saturated and trans fats
concentrated in meat, dairy, junk, and fast food.
So for example, acne patients should be encouraged to discontinue
any whey protein supplements they might be taking.
The relationship between milk and acne severity may be explained
by the presence in dairy of normal reproductive sex steroid hormones
or the enhanced production of growth hormones such as IGF-1.
And if you re like, "Wait, I gave up dairy a month ago and still no change,"
It should be noted that changes in acne due to any dietary changes
are likely to take at least 10 to 12 weeks, so you have to stick to it.
Not surprisingly, acne patients were more than twice as likely
to have a non-vegan diet compared to controls,
but the difference did not reach statistical significance.
So maybe the vegans were eating a lot of vegan junk?
But what about this: "Vitamin B12 Induced Acnes"
Our fellow great ape herbivores like gorillas get all the B12 they need
practicing the eating of feces, but my preference would be
to take B12 supplements. And you don't have to worry
about getting too much because there are evidently no reports
of adverse effects associated with excess B12 intake,
but that's not true.
First described back in the 1950's, about 1 in 10 people erupt in acne
within days or even just within hours of getting an injection of vitamin B12,
which then disappears rapidly when you stop injecting them.
At the time, we had no idea what the mechanism might be,
a problem still unsolved even up until just to a few years ago.
But then we finally figured it out: Vitamin B12 modulates
the gene expression of the skin bacteria that cause acne.
They swabbed the skin of 10 people before and after being injected
with Vitamin B12. It turns out the level of B12 on your skin
is proportional to the level in your blood, and so after injection
the bacteria on your skin have to make less of their own B12,
and so the acne bacteria could concentrate instead on using
its cellular machinery to churn out more compounds to attack your face.
Without excess B12 on the skin, shown here in green,
the bacteria has to make most on its own at the expense of porphyrins,
which can trigger acne inflammation. When there's lots of B12 floating around,
the bacteria can not waste resources and focus instead on trying to pimple
you up. OK, so wait, what do you do? Those on plant-based diets have
to take supplemental B12. Yes, but we don't have to get injections.
Vitamin B12-related acne tends to occur only in dosages in excess of
5,000 to 10,000 micrograms a week, well in excess of the 50 micrograms
a day I recommend, or alternately my 2,000
single weekly dose. I mean the only time you'd be taking
between 5,000 to 10,000 a week is if you were treating B12 deficiency.
If you remember from my previous video, B12 deficiency is treated with
1,000 micrograms a day for a month or more,
and that could potentially trigger it, as noted in this vegan woman
who wasn't taking B12, developed B12 deficiency,
and had to be treated with such high doses her face erupted in acne.
So all the more reason not to fall B12 deficient in the first place.
But look, if worse comes to worst, even if you do get B12 injections,
the likelihood of it triggering acne may only be about 1 in 10.
In 2019, a study found an “Association Between
High Intakes of Vitamins B6 and B12 From Food and Supplements With
(the) Risk of Hip Fracture Among Postmenopausal Women
in the Harvard Nurses’ Health Study.”
But note, it was only the combined high intake
of vitamins B6 and B12.
We know that treatment with high doses of vitamin B6
may alone increase hip fracture risk.
After a decade or so, those who had been taking
high dose B6 supplements had about a 40% higher hip fracture risk,
but not in those taking B12.
And that’s what the Harvard study found too—
high intake of vitamin B12 alone
was not associated with increased risk.
In fact, some observational studies suggest slightly
lower fracture risk at high B12 blood levels.
But what we care about most are interventional studies,
where people are randomized to B12 so we can see what happens.
And when you do that, no increased fracture risk
among those given B12.
In conclusion, based on randomized controlled trials,
high doses of vitamin B12 have not been shown
to be associated with the risk of fractures.
OK, but what about this?
In 2017, a study found that men taking vitamin B12 supplements
appeared to have an increase in lung cancer risk.
Now, they didn’t find any such association in women,
and it was mostly among smoking men.
Could it be that B12 was like feeding some budding tumors?
I mean, it’s hard to imagine a vitamin being carcinogenic
on its own, and especially somehow only in men but not women.
The bottom line is that replication of these ﬁndings
with additional studies is necessary,
and indeed when you put all the observational studies together,
there was no signiﬁcant correlation between the levels of B12
in the blood and lung cancer, whether you smoked or not.
If anything, most studies seemed to be trending
towards higher B12 levels being protective.
But then, in 2018, a new study found an association
between overall lung cancer risk and higher
circulating levels of B12,
again appearing to be more of a smoker thing.
Now, this was another observational study.
Those with higher B12 levels were just observed
to have higher cancer levels;
and so, those of you who have been following my work know the drill.
There are two potential issues that arise
in observational studies that prevent you from ascribing
cause-and-effect: confounding factors, also known as
“lurking variables” and reverse causation.
What might be a lurking variable in this case, a third factor
associated with both higher B12 levels and cancer,
that may be the true cause?
Well, who has higher levels of B12 circulating in their blood?
Those who eat lots of meat and dairy,
in fact probably the most important contributors.
And those who eat more meat do tend to have more lung cancer,
about 35% more risk for every about daily quarter-pound burger,
and 20% increased risk for each like, breakfast sausage link.
So, no wonder those with higher B12 levels in their blood
could have more lung cancer.
The B12 could just be a marker for meat intake.
And, if you remember, reverse causation is when
instead of X leading to Y, maybe Y is instead leading to X.
So, instead of high B12 blood levels leading to cancer,
maybe cancer leads to high blood levels.
And indeed, nearly three-quarters of cancer patients
exhibit elevated B12 levels.
So, elevated B12 levels may just be a marker for cancer.
There are all sorts of things beyond just taking extra B12
that can raise your levels: liver problems, kidney problems,
bone marrow problems, and cancer.
So, high levels may just be a marker of a brewing,
not-yet-diagnosed, cancer.
Yeah, but what about observational studies
specifically linking supplement use to lung cancer?
That too could be reverse causation,
where being at risk for cancer—in other words,
being a smoker—makes you more likely to take vitamins
to try to decrease your risk.
Basically, any behavior tied to smoking could be indirectly tied
to lung cancer, but it’s the smoking itself, of course,
that’s the real lung cancer risk.
So, we’re left with this chicken or the egg causality dilemma,
which is why ideally, we need randomized controlled trials
to see if there’s any cause-and-effect.
This became even more urgent with genetic evidence
suggesting that those just born with higher lifelong levels
may be at increased risk.
Thankfully we do have randomized controlled trials—
over a dozen randomized controlled trials
randomizing thousands of people up to 2,000 micrograms of B12
every single day for years and…
vitamin B supplementation does not have any effect on getting cancer,
dying from cancer, or dying overall,
and this includes specifically looking at lung cancer.
In fact, if anything, vitamin B supplements may actually lower
the risk of the most dangerous form of skin cancer.