Do you want improved immunity, higher energy levels, a sharper brain or better sleep? There’s a pill to be popped that promises that.
According to market researchers Mintel, 70 per cent of UK adults report having taken a vitamin, mineral or other supplement, fuelling an industry worth over £600million annually.
From multivitamins to magnesium, supplements have become a daily ritual for millions of us – a neat shortcut to better health. But despite the money we spend and the faith we place in them, they may not be doing what we think.
‘People expect that if they take a supplement, within a couple of weeks they’ll feel health benefits, but that’s not going to happen,’ says dietician Dr Carrie Ruxton of the Health And Food Supplements Information Service. ‘Our expectations have become far too high.’
Here’s what you need to know about why they might not be as effective as they claim – and which supplements, if any, you should really be taking.
‘People expect that if they take a supplement, within a couple of weeks they’ll feel health benefits… but that’s not going to happen’
Multivitamins won’t make up for a bad diet
A balanced diet, with protein-rich foods such as meat, fish, eggs and pulses, wholegrain carbohydrates, unsaturated fats, fruits and vegetables, should deliver all the vitamins and minerals your body requires. But since only two in ten adults eat their five-a-day, it’s tempting to imagine a daily multivitamin will bridge the gap.
Dr Ruxton says, ‘If you have a poor diet, multivitamins won’t make up for it. But it might lessen the negative impact of any deficiency – for instance in vitamin C, which can make your immune system less effective.’ This, she says, is the key message many of us have lost sight of. ‘Supplements aren’t drugs – they’re supposed to top up our diet. They were designed to help people with deficiencies hit the recommended daily amount, not to compensate for an unhealthy lifestyle or prevent disease.’
Are you taking enough vitamin D?
Essential for maintaining the health of bones, teeth, muscles and immune function, as well as enabling the body to absorb the bone-building nutrient calcium, vitamin D is the one supplement we should all be taking.
‘We can synthesise vitamin D from sunlight exposure on the skin, but most of us are low on it in this country,’ says Simon Gaisford, a professor of pharmaceutics at University College London.
The NHS recommends a daily ten-microgram supplement during the gloomy months of October to March, but Dr Ruxton says: ‘I take 25 micrograms a day all year round because I feel ten isn’t enough – it’s well within the safe upper limit of 100 micrograms.’
Is your supplement being absorbed?
How much of a vitamin or mineral your body absorbs can vary dramatically depending on the form it’s in, what you take it with and even your own gut health.
‘Different compounds, or forms of the same nutrient, are absorbed to different degrees,’ says Dr Ruxton. ‘For example, with iron, the best absorbed are iron citrate and iron sulphate – so it’s worth asking a pharmacist which to go for.’
Some minerals also compete with one another for absorption in the gut. ‘Calcium interferes with absorption of iron, for instance, so take an iron supplement on an empty stomach,’ says Professor Gaisford. ‘As a rule of thumb, take supplements containing minerals spaced throughout the day.’
By contrast, vitamins including A, D, E and K ‘must be taken with fats, so these are best taken with food, to aid absorption,’ he says.
Absorption can also be hindered by digestive issues such as irritable bowel syndrome and certain medications – so you may only be accessing a fraction of what you think.
You may be taking too much
More isn’t always better when it comes to supplements – and some can be harmful in high doses. Vitamin A is the one experts are most cautious about, as it’s stored in the body rather than excreted, meaning excess can build up over time. High intakes have been linked to liver problems, bone thinning and an increased risk of birth defects.
Vitamin D and iron can also accumulate if taken in large amounts. ‘This is why it’s important to stick close to recommended daily amounts and avoid “high-strength” formulas unless prescribed,’ says Dr Ruxton.
Pricey brands won’t make you feel better 
Dietician Dr Carrie Ruxton of the Health And Food Supplements Information Service
On social media it’s hard to miss adverts for premium supplement brands promising to transform the way you feel for as much as £100 a month. But a higher price doesn’t guarantee higher quality.
Dr Ruxton says that with multivitamins there will be no difference between an expensive and a supermarket own brand. ‘Sometimes, a premium brand can be slightly better for people with specific issues,’ she says. ‘For example, if you want a nutrient profile to support pregnancy or breastfeeding, they can give you more than a basic multivitamin.’
Many brands offer products marketed as ‘all-in-one’ menopause solutions to everything from hot flushes and brain fog to sleep, mood and energy. Studying the ingredients is vital, as some barely differ from standard multivitamins, despite costing far more.
‘I have not seen sufficient evidence that supplements are effective for these symptoms,’ says Dr Ruxton. ‘In most cases, they won’t do you any harm and some women report finding them helpful, but for others, HRT will be the most effective option.’
Find the right form of magnesium for sleep
According to the NHS we should be able to get all the magnesium we need from foods including nuts and seeds, leafy greens, pulses, yogurt and fish. But many people swear by taking it in supplement form to help them get a good night’s sleep.
Professor Gaisford is one of them. ‘I take magnesium glycinate as it’s the best option for absorption,’ he says. Magnesium oxide, commonly found in cheaper supplements, is absorbed far less efficiently than magnesium citrate or glycinate.
Does the formula make much difference?
From liquids and pills to powders and gummies, supplements are available in an ever-growing range of formulations. Water-soluble vitamins and minerals are usually solids, so are most often found in tablets, sachets or capsules, while omega-3 oils will tend to come in a liquid-filled, soft-gel capsule. ‘All will dissolve in the gut, so it’s a personal preference,’ says Professor Gaisford. Equally, if you prefer your vitamin D in a spray to a pill, there’s no evidence it will be absorbed any more or less effectively.
The four supplements experts swear by
As we get older, our ability to absorb vitamin B12 from our diet (in meat, fish, eggs and dairy) diminishes. Low levels can cause fatigue, so a supplement is a good idea for over 50s. Vegans should also monitor their levels.
As well as vitamin D and magnesium, Professor Gaisford takes omega fish oil capsules – because, he says, ‘Two omega-3 fatty acids, EPA and DHA, are essential and can be difficult to obtain in sufficient quantity in the diet, unless you eat a lot of fish.’
Dr Ruxton agrees, adding, ‘Fish oil is especially important for people aged 50-plus to support everything from brain to heart health.’ She also takes a daily probiotic. These purport to help restore the balance of ‘good’ bacteria in the gut and are being studied for their potential impact on immunity. ‘Before, I’d get around three colds per year. Since taking it, I’ve had one in the past two years.’
For people who aren’t sure their diet is up to scratch, both recommend taking a basic multivitamin – although, surprisingly, Professor Gaisford says, ‘You probably only need to take it once a week.’
New research, published in Nature Medicine last month, added a tentative note of support. A study of nearly 1,000 people, aged about 70, found that taking a daily multivitamin for two years slowed two of five biological ageing markers in older adults by an average of four months. The effect was modest but it suggests that for people with nutritional gaps, a basic multivitamin may offer some benefit.
Although as Dr Ruxton notes, ‘It’s the simplest way of topping up, but diet is what’s really important.’