/ Health

Do vitamins and supplements make you healthier?

Lots of people take supplements to boost energy or keep joints healthy. But our investigation found that there’s a chance that they might not always have the health benefits you’d expect.

When we looked into the health claims on the packaging of certain supplements we found that the ‘key ingredient’ might not deliver on the health benefit you might gather from reading the label.

In fact, we found that a multivitamin you could pick up in any supermarket for a lower price could often do just as much good as a supplement designed for specific complaints.

Do you check the label?

Many people take supplements – and in our survey of 3,422 Which? members who do, cod liver oil and other fish oils were the most commonly used, with six out of ten of you taking them.

However, our investigation found that no special health claims can be made about cod liver oil at all – this might be surprising, especially as half of the people we surveyed think that it helps to support joints and cartilage.

In fact, the active ingredient in the tablet that’s contributing to your joint health is actually vitamin D – which is naturally present in cod liver oil, but can also be found in other cheaper multivitamins.

It was much the same story with co-enzyme Q10, taken by one in ten of those we surveyed. This is often promoted as an energy supplement, but this is often down to B vitamins in the tablets rather than the co-enzyme Q10 itself.

You’d have to squint to find out the vitamin ingredients on the back of the label of some supplements, as they aren’t always listed at the front. But it’s important to check and see exactly what it is that you’re taking.

Bad reactions to supplements

Some of you told us about problems you’ve had after taking supplements, like skin irritation after taking vitamin B6, and a laxative effect possibly caused by magnesium in a supplement.

But we found that there is no systematic way of recording these side effects and finding out how common they are. With no official reporting system that catalogues side effects or bad reactions to vitamins, unlike medicines or herbal supplements, it’s difficult to know what your risks are from taking these products.

So do you take vitamins and/or supplements, and if so, do you find them beneficial? And have you experienced a bad reaction to a supplement before?


I used to have terrible cramps at night in my left leg when sleeping. Ever since taking ‘Ginkgo Biloba’ and a full dose of multivitamins (so long ago I cannot remember when) I have never had this problem since.

I take cod liver oil capsules ( what is the gelatine doing to me ? ) and a multi-vitamin.
My GP says there is absolutely no evidence that they do any good, however they are cheap !

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If you eat a balanced meal you really do not need to be conned by these companies getting you to buy these expensive supplements. IT MAKES THEM LOTS OF MONEY. Mostly these supplements go straight through you if you take them with water. As a retired personal instructor the best advice I can give to men is eat a teaspoon of good tomato puree a day. Helps look after the prostrate gland, but it must be taken daily.

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Not many days go by without a tomato or two on the plate, but I had never thought of taking it in concentrated purée form; it doesn’t appeal so much although I consider it much more sensible than getting locked into a regime of dubious and expensive supplements

I have no rational need to worry about prostate problems at the present time but it is the one thing I think about more than others; perhaps a daily purée portion will help to reassure me.

I took a multivitamin tablet and a cod liver oil tablet daily for about two years. I did not notice any difference to my health or joints.
I stopped the supplements approximately eighteen months ago. Once again, there was no noticeable detriment to my health or joints.

If we have an adequate diet we don’t need vitamin supplements, but what is an adequate diet? In the potato famine, many of the people died of scurvy, having relied on potatoes for vitamin C. They were not starving but their carbohydrate source had been replaced with maize which has no Vitamin C. Scurvy would have been known in ports, but at least one inland doctor decided that the superficial resemblance to scurvy was misleading and continued to treat it “successfully” with mercury.
Vitamin D is especially problematic. The levels in people fall from the Mediterranean northwards through France. This decline continues to the Northern Isles. The shorter winter days and the increased cloud cover make it difficult for us to make enough Vitamin D from sunlight alone in the UK. MS increases inversely, peaking in the N.W. When humans left Africa for Europe they were black. Natural selection has completely removed the genes for black skin from Northern Europe, a process that required the removal of around 50 to 100 times the affected population, say 15% to 25% of each generation for 400 generations. The level of Vitamin D required to avoid rickets is a lot lower than we would have if we ate a Mediterranean diet outside in short sleeves in blazing sunshine beside the Mediterranean. Europeans are mostly lactose tolerant too, and can get some vitamin D from milk, another recent triumph for natural selection.

‘Chips with everything’ is a popular criticism but they will provide vitamin C for many who eat little fruit & veg. It is the vitamin that cannot be stored, so it’s best to have some every day. Eating oily fish once or twice a week should provide adequate vitamin D during the winter months. Sometimes vitamin deficiencies are caused by what medications we are taking and if we have certain illnesses. I would like to see people being tested to see if they have a deficiency of vitamin D in particular, rather than dosing themselves with vitamin pills ‘just in case’. It might raise awareness of eating appropriate foods if after testing we came away from the GP’s surgery with a ‘prescription’ to visit the fish counter and greengrocery section of the local supermarket.

I love chips,,,,,,,,,,,,,,I have loved chips since the days we had a bit pot of lard………….Now of course we have the niceties of a modern device way superior….and safer
I also love melon,,,apples, the little cox in particular,,,pears,,,strawberries and various veggies and I am so thankful for the supermarket we go to for having shelves full of yummy stuff in good condition but the price of melons just now is a little high
I do like spuds also but they are a bit boring seeing that I cannot eat dairy………..Still I have spuds with a little touch of sea salt regular

Problems with eating dairy foods are usually caused by lactose intolerance but can be genuine allergies, occasionally serious. Lactose intolerance varies between people and some can consume small amounts, in which case there it’s just a case of knowing how much you can eat without problems. If you have to completely avoid dairy products, it’s important to eat other foods to provide the vitamins and minerals present in milk and diary products. http://www.nhs.uk/Conditions/lactose-intolerance/Pages/Introduction.aspx

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p williams says:
15 February 2016

Yes I take 8 supplements a day. Whether they have any effect is unknown!

I get my supplements from Healthspan who I find very good and give good advice I am 75 and lead a full and active life with plenty of exercise but find the need for supplements for a variety of problems related with age

I’m looking at an article from the Eastern Daily Press dated July 2001 which details the losses in vitamin and minerals in fruit and veg over the previous 50 years due to modern farming methods. A study carried out by qualified nutritionist David Thomas showed that such nutrients as Magnesium, Potassium, Iron, Calcium and Copper are now up to 75% lower than they were in a variety of fresh fruit and veg back in the 1950’s. There is an optimum level for each and every nutrient for each and every individual depending on age, sex and lifestyle, trouble is that without a detailed and exhaustive testing programme it is impossible for the average person to determine what she or he really needs. Bear in mind that as we age our ability to fully utilise certain nutrients tends to wane. My view is that judicious use of certain supplements is an insurance policy against going short on some of the most important ones such as the anti-oxidants vitamins A, C and E, and unless one eats oily fish on a regular basis an Omega 3 supplement is probably a good idea. Eat as wide a variety of fresh fruit and veg as you can and avoid highly processed ‘foods’ and added sugar as much as you can and (barring serious accidents) you’ll probably thrive!

Whether or not mineral and vitamin levels have declined (and this is contested by the farming industry) what matters is that our intake is sufficient. If a nutrient is essential, consuming more than you need is not necessary beneficial. For example, it would not be beneficial for most of us to have more sodium (which is present in salt). Maybe some of us are not getting enough of certain minerals but just assuming that more is always better is not a sensible approach.

According to a Guardian article, David Thomas sells mineral supplements. 🙂

Another case of Which? asking an NHS Dietitian who has never received training on how to use food supplements – aside of those prescribed by the NHS – and, thus, another biased article. Health matters are much more complex than electrical appliances, so this is another perfect example of why you should not bother reviewing them.

Hopefully dietitians are trained to help people use foods to provide the nutrition they need, without supplements wherever possible. At least NHS dietitians are unlikely to have any links with sales of supplements whereas I am always wary of those that recommend them. Which? looks at many products and helps make us aware of potential problems.

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The problems with vitamins and certain minerals is that they are essential, but that does not mean that it is wise to take more than is provided by a reasonable diet unless a need has been demonstrated by testing. For those who have not knowledge about human biochemistry, perhaps take a crude analogy of the role of oil in a motor car. An engine won’t run long without it but put in too much and you risk wrecking it. If more people studied biochemistry they might begin to realise the complexity of cellular processes and the possible risk of affecting their health by swallowing supplements that may do more harm than good.

Wavechange, to my knowledge NHS Dietitians are not trained in the use of supplements above RDAs and often don’t see the point. It’s taken 20 years for Public Health England to issue a recommendation for supra-RDA amounts of vitamin D supplementation over the winter months, where the “evidence” for the need of this simple intervention has been clear for a long time. So now that PHE says we should all dose up on vitamin D during the winter “it’s OK” to do so, but many NHS dietitians would have been totally against “pill popping” until the day before PHE’s announcement… If dietitians were trained to identify the genetic traits that may make a person more or less of a prone to vitamin D deficiency and checked for vitamin D levels once/twice a year to check that that genetic trait was actually manifesting itself, they’d be the right people to invite onto an expert panel for this kind of discussion. Considering RDAs apply to everyone regardless of their genetic makeup in 2016 is not only outdated, but also unethical and dangerous. For example, how is PHE planning to mitigate the damage done by taking 20 years to issue a recommendation to take vitamin D during the winter months? What about the loss of quality of life experience by those who could have benefited from that advice years before? I know about this idea that we get every nutrient we need from the food we eat. But do we? Do you, do I?

As to the discussion about links with supplement companies, etc. is a completely different matter. Some key dietitians (well known for their online media presence in the UK) are advisors to supplement manufacturers (e.g. Boots) and have been seen to tweet along the lines of “Boots supplements are cheaper than other brands”, then sneakily deleting that tweet a little later. Such a statement shows a complete lack of knowledge, and the fact that this is not a dietitian’s area of expertise. If Which? wanted to keep this type of conversations factual and free of bias, you should invite a number of professionals who actually know about supplementary nutrients and their interaction with genes to be part of your panel. And yes, that should include geneticists.

I very much agree on the need to review official advice in the light of the current balance of scientific evidence and that NHS staff should receive training to keep them up to date. Many have pushed for this.

I am also strongly in favour of routine testing and as you have pointed out, some individuals are are greater risk of deficiencies. One of the best examples of the advantage of routine testing is the HbA1c test, which has identified a huge number of people with or at risk of developing diabetes. Even before this test was available, conventional blood glucose tests and tolerance tests could have prevented needless suffering and probably saved a great deal of NHS funds. Our GPs could do a lot to help by reviewing the need for long-term prescription drugs, which can many side effects – some known and others yet to be discovered.

The quality of life is undoubtedly important and I am not opposed to use of supplements where there is evidence of need, but now that many supermarkets offer hundreds of products on open sale and we have high street stores and online traders offering even more choice, I think it is time to question the way we are heading.

I believe that any professional found promoting commercial products should be reported, though I am not certain of how to go about doing this.

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I have not even looked for information, Duncan. I have family and friends in the NHS and well remember when GPs received generous gifts that might have encouraged them to prescribe certain products. As far as I know there are now strict rules to prevent the practice. I was unaware of NHS employees promoting companies online until Helena mentioned the problem.

Hugh_F says:
25 March 2019

I once researched Vitamin D. Levels of Vit. D fall in humans as you travel North from the Mediterranean, and are pretty low by the time you get to the dull cloudy Scottish isles. It is one factor making Glasgow and NW Scotland the sickest part of Europe, and also helps explain why a Mediterranean diet is so good, especially eaten outside in the sunlight near the Mediterranean. One researcher calculated that there is too little sunshine in December North of Algeria for a typical person to synthesise vitamin D as fast as they use it up. The only primates living outside the tropics are omnivores (e.g. crab-eating macaques and humans). Far and away the best source of vitamin D3 is oily fish, without which it would have been difficult for humans to colonise places like North Norway. The plant vitamin D2 is much less easily used so you would need about 3x to10x as much of it, depending on who you ask. The best chemistry I found suggests 10x. People with dark skin need much more sunlight to make adequate Vit. D. If their natural skin has a factor of 20x, so is a good sunscreen, they would need 20x as much exposure to the sun as someone with white skin. This explains why the first human colonists to travel North lost their dark skin pigments. Calculations show that about 100 times the entire population of Europe must have selectively “died”, meaning they failed to pass on their genes, because they were dark skinned in a habitat with little sunshine. That is about 5%, 1/20, on average per generation for 50,000 years. Wearing a black burka and not eating fish is clearly very risky in the UK. Most North Europeans are lactose tolerant, a condition that has evolved over the last several 1000s of years. Milk, or rather cream, is another source of Vit. D. About 3 or 4 time the population “died” because could not drink milk without getting intestinal problems. Those who could drink milk were more successful at reproduction and so replaced most of the lactose intolerance genes. This all happened before vitamin tablets were available, but if should remind us that we do need vitamins from somewhere.