Vitamin pills taken by half of all Brits are a waste of money, according to new research. The health benefits are all in the mind - and some may even do more harm than good, say scientists.
In the UK up to 46 per cent of adults pop supplements on a daily basis. The industry is worth nearly £500million a year. The US research team say there's no "magic set of pills to keep you healthy." Diet and exercise are key.
Lead author Dr Jeffrey Linder, of Northwestern University, Evanston, Illinois, said: "Patients ask all the time, 'What supplements should I be taking?' They're wasting money and focus thinking there has to be a magic set of pills that will keep them healthy when we should all be following the evidence-based practices of eating healthy and exercising."
Multivitamin tablets are particularly popular as they contain a mix of a dozen or so vital nutrients. The Health Food Manufacturers' Association says more than a third of people feel they do not get all they need through their diet.
Daily supplements such as Maximum Human Performance, Wellman and Vitex are hugely popular in the UK. But a systematic review of 84 studies found "insufficient evidence" that taking multi-vitamins, paired or single supplements prevent cardiovascular disease and cancer.
It was carried out by the United States Preventive Services Task Force (USPSTF), an independent panel of experts that makes evidence-based recommendations. Dr Linder said: "The task force is not saying 'don't take multivitamins,' but there's this idea that if these were really good for you, we'd know by now."
They specifically advise against popping beta-carotene supplements because of a possible increased risk of lung cancer. Dr Linder said: "The harm is that talking with patients about supplements during the very limited time we get to see them, we're missing out on counselling about how to really reduce cardiovascular risks, like through exercise or smoking cessation."
Drawn to the allure of filling nutritional gaps in their diet, people in the US spent nearly $50 billion on vitamins and dietary supplements last year. Writing in JAMA, Dr Linder and colleagues say more than half of American adults take them - with their popularity projected to increase.
Eating fruits and vegetables is associated with decreased cardiovascular disease and cancer risk, they said. So it is reasonable to think key vitamins and minerals could be extracted and packaged into a pill - saving trouble and expense of maintaining a balanced diet.
But whole fruits and vegetables contain a mixture of vitamins, plant chemicals, fibre and other nutrients that probably boost health by acting in together, they explained. Micronutrients in isolation may act differently in the body than when naturally packaged with a host of other dietary components.
Dr Linder noted individuals who have a vitamin deficiency can still benefit from taking dietary supplements such as calcium and vitamin D. They have been shown to prevent fractures and maybe falls in older adults. The revised guidelines do not apply to women who are pregnant - or planning a family.
Co author Dr Natalie Cameron, an instructor of general internal medicine at Northwestern, said: "Pregnant individuals should keep in mind these guidelines don’t apply to them. Certain vitamins, such as folic acid, are essential for pregnant women to support healthy foetal development.
"The most common way to meet these needs is to take a prenatal vitamin. More data is needed to understand how specific vitamin supplementation may modify risk of adverse pregnancy outcomes and cardiovascular complications during pregnancy."
Recent research has found most women in the US have poor heart health prior to becoming pregnant. Dr Cameron said discussing vitamin supplementation and optimising cardiovascular health prior to pregnancy is an important component of pre-natal care. But healthy eating can be a challenge when US food manufacturers focus on processed products packed with fat, sugar and salt.
Co author Dr Jenny Jia, also from Northwestern, said: "To adopt a healthy diet and exercise more, that's easier said than done, especially among lower-income Americans. Healthy food is expensive, and people don't always have the means to find environments to exercise - maybe it's unsafe outdoors or they can't afford a facility. So, what can we do to try to make it easier and help support healthier decisions?"
Dr Jia has been working with charitable food pantries and banks that supply free groceries to help people pick healthier choices and encouage donors to provide healthier options or money. The NHS says other than women hoping to conceive, the elderly and under fives, supplementary vitamins are surplus to that already gained through diet.
