Updated 19 February 2013

To B12 or not B12?

Celebrities swear by the energising effect of the vitamin B12 injection. A doctor examines the facts.


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.

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 sky-high careers.

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-than normal 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 products.

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) any remaining 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 water soluble substance, any excess B12 is immediately excreted. So over-zealous B12 supplementation achieves nothing more than expensive urine.

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.

These 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 B12 boosting?

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 being treated.

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.

Symptom sorter

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 . . .

  • Fatigue
  • Anaemia
  • Signs of muscle weakness, balance problems, abnormal sensations and other neurological problems
  • Memory loss
  • Clear signs of depression
  • Shortness of breath
  • Angina
  • Decreased appetite

These symptoms are rapidly reversed with treatment through vitamin B12 replacement.

(This is an extract of an article that originally appeared in theYOU Pulse magazine)


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