The vitamin B12 injection has been hailed a
miraculous energy enhancer – but also deemed
a big, fat fake. Now some doctors say unless you
have a rare B12 deficiency, the only benefit of
this shot is the placebo effect
By Dr Anna Hall
Madonna. Britney Spears. Lindsay Lohan.
No, this is not just a line-up of controversial
celebrity blondes. It’s a selection of stars who
regularly have vitamin B12 jabs to keep
their energy levels in line with their
And they’re not alone. In fact, we’re all searching for an elixir to
override nature’s systems and provide an instant fix. Today’s athletes use
performance-enhancing drugs and high-stress execs pop pills and
potions to boost performance and rev their energy engines.
This quick-fix attitude aims to artificially inject a better-thannormal
effect – and much faster than anything that can be achieved
naturally. And the vitamin B12 injection is lauded by many as the
quickest energising fix around.
You may not be a superstar, but that doesn’t mean the stresses and
strains of modern life don’t leave you gasping for an energy boost.
Could this contentious jab be just what the doctor ordered?
Is more really called for?
Vitamin B12 (one of a group of eight B vitamins) is used by every cell in
the body because it plays a role in the production of DNA. It’s also
essential for the normal functioning of the brain and nervous system,
and in the formation of blood cells. But as the body can’t manufacture
vitamin B12, it has to be obtained from one’s diet – mainly from animal
How much B12 do you really need? For adults, two to three
micrograms per day is enough to keep all the B12 reactions running
at full tilt. Any excess B12 goes into the stores (mainly in the liver)
and when the stores are full (at around 5 000 micrograms) anyremaining B12 is simply excreted via the urine.
This means that injecting vitamin B12 when there’s no
shortage is senseless and wasteful. Why? Because the amount
stored in the liver is enough to last an average adult several
years before symptoms of deficiency arise.
Plus, being a watersoluble
substance, any excess B12 is immediately excreted. So
over-zealous B12 supplementation achieves nothing more than
Could you be B12 deficient?
As most of us have enough of this vital vitamin in storage, the
only people who really benefit from B12 injections are those
who suffer from a real deficiency – strict vegetarians, heavy
drinkers, individuals undergoing stomach surgery, people with
cancer, intestinal parasites or pernicious anaemia, and those on
medication such as anti-diabetic drugs or some antacids.
factors all lead to low levels of vitamin B12 in the cells.
If you have low B12 levels due to one of these factors, you’ll
probably need regular B12 injections. Once your stores are
restocked, an injection every two to three weeks will keep the
balance in check.
The B12 boom
If so little B12 is needed, and providing extra doesn’t speed
up reactions and can’t even be stored, why the hype around
One possible explanation (common to all therapies) is the
placebo effect: it works partly because you believe in it. This
is a powerful factor not to be ignored, and could explain why
devotees really do feel energised after a B12 shot.
The other possible explanation lies in inaccurate testing.
So-called pseudo-B12 substances are found in some plant
sources often taken as health supplements (such as spirulina
and other algae).
These have no biological activity in humans,
but may register as B12 on tests, falsely showing that the
patient has enough B12. Such a patient may have a slight
vitamin B12 deficiency, so a B12 injection will have a dramatic
effect simply because an unrecognised deficiency state is
When a good jab goes bad
The real danger is that uncontrolled, regular B12 injections
may disguise a true deficiency state where there’s a serious but
potentially treatable cause – such as pernicious anaemia,
cancer or alcohol abuse. And sometimes a delay or absence of
treatment could be fatal.
Science has clearly shown that consuming more vitamin B12
than your body needs doesn’t increase energy levels.
It’s also true that you can’t overdose on B12, so there are no
known toxic effects from using large amounts.
In short, if you have a true deficiency, using vitamin B12
regularly will be necessary and will certainly make a difference.
But for those of us who are not truly deficient, beefing up
our B12 intake will probably only benefit the manufacturers of
the product in the long run.
Check your B12 status
before looking for a
quick-fix energy boost.
If you’re suffering
from a vitamin B12
deficiency, you’re likely
to experience . . .
- Signs of muscle weakness,
balance problems, abnormal
sensations and other
- Memory loss
- Clear signs of depression
- Shortness of breath
- Decreased appetite
These symptoms are
rapidly reversed with
vitamin B12 replacement.
What is Vitamin B12?