Do you need a multivitamin? An honest answer

The multivitamin is the default supplement. It is what people buy when they know they should probably do something and are not sure what. That is precisely the problem with it.

The short answer

For most people eating a reasonably varied diet in the UK, a multivitamin is insurance against a shortfall they have never actually established they have.

It is not harmful. It is generally not doing much either.

Why the logic does not hold

A multivitamin contains twenty-odd nutrients in modest amounts. You are almost certainly not short of twenty things. You might be short of one or two, and if you are, the amount in a multivitamin is often not enough to matter anyway.

Take the clearest UK example. The NHS advises 10 micrograms of vitamin D daily through autumn and winter. Plenty of multivitamins contain considerably less than that. Someone taking one every morning through January in the belief they have covered it may well not have. We wrote about that in vitamin D in the UK.

So the product that feels like the safe general answer is frequently the wrong answer to the one question that actually applies to everyone in this country.

When a multivitamin does make sense

• Genuinely erratic eating. Shift work, illness, appetite loss, long stretches of poor meals. Broad, low-level cover is reasonable when the diet is unpredictable.
• Recovery from something. Where a GP or dietitian has suggested it.
• Real convenience preference. Some people will take one tablet and will not take four. A multivitamin taken daily beats a perfect stack in a cupboard.

When it does not

• You have a specific, identified gap. Then take that thing at the right amount, not twenty things at token amounts.
• You are using it to offset a poor diet. It does not work that way, and the things it cannot replace - fibre being the obvious one, where only about 4 in 100 UK adults hit the recommendation - are exactly the things that matter most. See how much fibre a day.
• You are already taking other supplements. This is where people quietly double up without noticing, because the multivitamin contains a bit of everything.

If you do take one

• Check the amounts, not the list of names. Twenty-five nutrients at trivial doses is a marketing feature, not a nutritional one.
• Check overlap with everything else you take. The upper limits matter - 100 micrograms a day for vitamin D, and 400mg from supplements for magnesium.
• Take it with food. The fat-soluble vitamins - A, D, E and K - are absorbed better that way.

The better question

“Should I take a multivitamin” is the wrong question, which is why the answers are always so unsatisfying. The useful one is narrower: given what you eat, where you live and what you are asking your body to do, what are you actually short of - and does that answer change as your training and your diet change?

That is a harder question. It is also the only one worth answering. Here is how to work through it.

General information, not medical advice. If you are pregnant, have a health condition or take prescription medication, speak to your GP or pharmacist.