/ 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?


The only vitamin we keep is Vitamin C 1000mg.

We take it for a few days at the first sign of a cold or if someone sneezes over us or when flying. I haven’t had a bad cold for at least 25 years when someone told me how good it was.

It is also stops cold sores developing if I take them immediately I feel my lip quivering.

I don’t think it is a good idea to take any of these supplements on a regular basis as there is plenty of information online to suggest they can upset the bodies balance.

But I definitely can’t eat 70 oranges that is supposed to be the equivalent of 1000mg of vitamin C so not a problem taking them just for a few days.

Hi alfa, the late American professor of chemistry , Linus Pauling originally recommended the use of vitamin C for the prevention of colds. If I recollect correctly this was in the 1960’s. More recent medical evidence does not support professor Pauling’s recommendation and GP’s certainly do not recommend it. A normal balanced diet contains plenty anyway. It is present both in veg. and fruit. As a retired GP I am not aware of any evidence that vitamin C can prevent cold sores. You may like to have a year without the supplement! ( Complete absence of vitamin C from the diet causes scurvy which can be lethal. Hence, in the past sailing ships on long sea voyages always carried a supply of apples).

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Dave, if you read my post properly, I don’t take vitamin C on a regular basis. I probably take less than a dozen tablets in a year.

Next time you feel a cold coming on, try it and you might just get no more than a few sniffles.

Seems a very strange article to post on the day that it is announced that the Scottish Parliament is considering adding folic acid to flour.

I think we can quite reasonably take a view that as many foods are already incorporating vitamins and supplements by Government edict. The question is are there others that should be added or have we got the right amount from our current lifestyle and diet.

Many countries add Vitamin D to milk, lack of folic acid and birth defects has been known in the UK since 1985. There is no doubt there are dubious and contrary research results out there however I have no doubt that given 5-10 years we will be giving better advice and also advising that all peoples metabolism are different rather than realising on averages.

As you say, people differ. That’s why it makes sense to test people if a vitamin deficiency is suspected. If my memory you told us that you had arranged your own vitamin D testing, Dieseltaylor.

We all need vitamins for health but may get all we need from a decent diet. That’s my approach, and if I was concerned about my health I would arrange to be tested.

Although vitamins are essential, taking more than we need may not be beneficial and could be harmful. It frightens me to see the shelves of vitamins etc in the supermarkets.

Holland & Barratt , owned by theCarlyle Group are the largest UK seller of supplements and have made the Press this last week on “requesting” cost reductions from their suppliers.

“Holland and Barrett is being accused of squeezing small businesses after it sent a letter to suppliers demanding contributions to its investment plan. In a letter this month, seen by the BBC, the high street retailer says it wants a reduction of costs of at least 5% from all its suppliers. It also wants suppliers to pay for £3m worth of security tags and CCTV. ” BBC

Perhaps they are gearing up for a flotation later this year. Last year they made much: ” The firm, which is based in Nuneaton , saw sales rise by 11.7 per cent to £513.6million for the year ending September 2015, with profit before tax up by 12.2 per cent to £146million” Coventry Telegraph.
A very very good return on sales.

In the US this recent report from the NY DA might give pause for thought until one finds out are things different in the EU. As for those who like to buy from the US ……
“Of all the store-brand herbal products tested from these stores, only 21% turned up DNA from the plants listed on the products’ labels, while 79% of the results showed either no DNA related to the labeled content or turned up contamination from other plant material, including rice, beans, pine, citrus, asparagus, primrose, wheat, houseplant, wild carrot, and others.

For the testing, researchers obtained multiple samples of each of the six supplement types — Gingko Biloba, St. John’s Wort, Ginseng, Garlic, Echinacea, and Saw Palmetto — and tested each sample five times. In all 78 samples were tested 390 times.”

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It’s crucial to take only those vitamins you really need. Taking multivitamins in a standard dose can be extremely harmful.

They can also interact with prescription medications, and there is an article about this in the April issue of Which? magazine. It’s often assumed that since vitamins are essential for health, taking more is beneficial, but that might not be the case, especially with some of the high dose vitamins on sale.

Reader View: Vitamins Healthy Or Harmful? Which February 2016

Dear Which,

As a which reader for many years, I was very disappointed with the poor quality of the article “vitamins: healthy or harmful?” which appeared in your February 2016 issue.

The main problems were:

1. The available evidence was heavily filtered to support a particular point of view.

2. Some of the advice given is many years out of date, and now considered contrary to good practice.

3. There were factual errors in some of the basic science.

Overall, I was very disappointed that Which chose to publish this.

Healthy Diet

There is very strong evidence that a poor diet and lack of exercise is responsible for around 80% of cancer and a similar proportion of heart disease. A good review of the evidence is given by the World Cancer Research Fund. (http://www.wcrf-uk.org/uk/preventing-cancer/ways-reduce-cancer-risk).

The high prevalence of cancer and heart disease is a strong indication that the majority of people do not have a healthy diet.

An excellent study on the population effects of diet, describing results for 50,000 people is contained within the book: “The China Study” by Colin Campbell.

The minimum vitamin RDA levels were developed many years ago to indicate the minimum levels of vitamins needed to prevent diseases such as scurvy and rickets. They RDA does not indicate the level of vitamins needed for a healthy lifestyle.

The article is correct in saying that increasing intake of vitamin D has a range of benefits. There is also extensive evidence for the benefits of other vitamins.


The phrase evidence is used in clinical circles to mean a variety of different things.

Pharmaceutical companies use the word evidence to refer to large-scale randomised controlled trials carried out on a univariate basis. There is considerable debate in the literature as to whether this approach is driven by science or economics.

Large-scale randomised controlled trials can only be carried out on drugs that will be sold at a high cost. There has at times been conflict between the NHS and the pharmaceutical industry for their refusal to carry out trials on cheaper drugs.

A large proportion of treatments delivered by health services worldwide has not been tested by large-scale randomised controlled trials.

Other forms of evidence include:
• small and medium scale clinical trials carried out on a univariate or multivariate basis
• population studies
• chemical pathway analysis

Health Risks

The article is correct in saying that high levels of vitamin A can be harmful.

The article is 20 years out of date in encouraging the reader to eat red meat. The evidence is now that this increases bowel cancer risk, and the recommendation is to minimise the consumption of red meat.

The article is 10 years out of date in encouraging the reader to eat dairy products. High levels of dairy products increase the risk of a variety of diseases. It is better to increase calcium intake from vegetables.

The article is correct in saying that people should take care when using any pharmaceutical or vitamin in conjunction with chemotherapy or warfarin therapy. There is always a risk of complications in the complex interactions that can occur. This does not however mean that the pharmaceutical or vitamin is harmful to a person who is not using chemotherapy or warfarin therapy.

Basic Science Errors

The statement that natural vitamins are the same as synthetic vitamins is basically wrong. Many complex biochemical molecules exist in multiple forms.

I enclose a quotation from Wikipedia:

“An isomer (/ˈaɪsəmər/; from Greek ἰσομερής, isomerès; isos = “equal”, méros = “part”) is a molecule with the same chemical formula as another molecule, but with a different chemical structure. That is, isomers contain the same number of atoms of each element, but have different arrangements of their atoms.[1][2] Isomers do not necessarily share similar properties, unless they also have the same functional groups. There are many different classes of isomers, like positional isomers, cis-trans isomers and enantiomers, etc. (see chart below). There are two main forms of isomerism: structural isomerism and stereoisomerism (spatial isomerism).”

The biological action of any molecule in the body depends on both the chemical structure and the physical structure. Biological processes tend to produce a single isomer, i.e. a single physical shape. Chemical processes tend to produce multiple isomers. Different isomers have different biological properties.


I have fears that in a fast moving area of medical research Which? is actually on to a loser being a source of advice on these matters. As pointed out by others repeating strongly that ” good diet and you should be OK” and then links to parts relevant such as my copying of the NHS on Vitamin D would be a way to approach the matter.

This Conversation could be the basis of a simple intro to the subject followed by a nice CAWiki article which could give all the necessary links to the underlying resource, that could be pulled up by a subscriber instantly. I see Which? missing the boat with this article and interesting inputs, and the magazine article becoming difficult to find on the Which? site and of course as they are not up-dated increasingly of less value

Given the results in the US on bogus Vitamins and supplements that WOULD be a product testing role foe Which? to be active in. I realise that testing has cost implications however I do believe some of the continental consumer , and possible regulatory, bodies, may already cover this area.

It might be a consideration that testing them at all indicates a belief that they have value. to consumer which presents a policy decision. I actually do consider that some are beneficial for some people. Most particularly Vitamin D as we see rickets re-surfacing in the UK and more elderly people with increasingly limited ability to create Vitamin D through sunshine.

Eating fish works very well but is significantly more expensive than a 10p pill,

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Duncan,,,I doubt if todays lot could swallow cod liver oil……….Prob only capsules……I can drink it like water because like you I was brought up with it…………..I dont remember the NHS orange those but I do remember the Vit C orange flavoured tablets……….
I have cod liver oil near every day to date……….

born in 1944- we had cod liver oil, malted milk and pure orange juice in bottles. All these came free of charge from our local health clinic.

Yes vitamins help. So does good quality ones, which I mention after seeing one in your leading article I know to carry synthetic sweeteners. One particular one stops my hair going grey and another helps me when I sometimes get constipated.

Looks like the NHS believe in supplements and actually advise a large chunk of the population to take Vitamin D. Seems to make a point.

” How much vitamin D do I need?

Most people should be able to get all the vitamin D they need by eating a healthy balanced diet and by getting some summer sun.

Groups of the population at risk of not getting enough vitamin D are:

all pregnant and breastfeeding women
babies and young children under the age of five
older people aged 65 years and over
people who are not exposed to much sun – such as people who cover up their skin when outdoors, or those who are housebound or confined indoors for long periods
people who have darker skin, such as those of African, African-Caribbean and South Asian origin

What does the Department of Health recommend?

The Department of Health recommends that:

all pregnant and breastfeeding women should take a daily supplement containing 10 micrograms (0.01mg) of vitamin D, to ensure the mother’s requirements for vitamin D are met and to build adequate foetal stores for early infancy
all babies and young children aged six months to five years should take a daily supplement containing vitamin D in the form of vitamin drops, to help them meet the requirement set for this age group of 7-8.5 micrograms (0.007-0.0085mg) of vitamin D a day
babies fed infant formula will not need vitamin drops until they are receiving less than 500ml (about a pint) of infant formula a day, as these products are fortified with vitamin D
breastfed infants may need to receive drops containing vitamin D from one month of age, if their mother has not taken vitamin D supplements throughout pregnancy

People should also take a daily supplement containing 10 micrograms (0.01mg) of vitamin D if they:

are aged 65 years or over
aren’t exposed to much sun – for example, those who cover up their skin for cultural reasons, who are housebound or confined indoors for long periods

You can buy single vitamin D supplements or vitamin drops containing vitamin D (for use by under-fives) at most pharmacies and supermarkets. Women and children who qualify for the Healthy Start scheme can get free supplements containing the recommended amounts of vitamin D. “

dieseltaylor, you have quoted correctly the NHS advice regarding vitamin D but you seem to suggest that the NHS believes in all other supplements which is not the case. Most of the supplements in pharmacists shops are not necessary for folk on a well balanced diet.

Vitamins and certain minerals are essential but it’s a dangerous assumption that if something is good, more must be better. Unfortunately few in the population know very much about biochemistry and the effects of these dietary supplements. Salt is essential and if it was not for the fact that most of us get rather too much in our diet, salt pills would be sold in health food shops. A small amount is good for us but larger amounts are harmful. It’s like oil in car engines – you need some but too much will cause damage.

There’s a lot of nonsense about supplements online, often from companies that profit from selling them. I would prefer to follow the guidance offered on the NHS website and hope that this will be kept up to date as our knowledge advances. As Dave says, there is useful advice on vitamin D, but most supplements are not needed by people that are eating a reasonable diet.

Sorry – It was Dieseltaylor who posted the information on vitamin D from the NHS website.

I have Multiple Sclerosis and take vitamin D tablets and I do feel much better in myself since I increased my daily intake to two a day.

I have noted that calcium tablets from Holland and Barrett after 22 hours in my body are passed out in the same shape as they went in and have to be fished out from the WC as they will not flush away. I reported the batch number to H&B and they say they are checking it. I tried to dissolve a tablet in recently boiled water and it failed to dissolve. I no longer use calcium tablets and have thrown the remainder away. I would be interested if others have had this experience.

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Well done to Which? for at least having a go at the complex area of Supplements ( much overdue)
Disappointing nothing about Glucosamine.
The big on-line order people like Healthspan not mentioned, yet bet loads of members use them.
Big thing is the firms can put this and that on the packaging but we don’t really know the actual ingrediance or quality inside each tablet.

As a layman in good health (I think) it seems to me that given a balanced diet we should not need any supplements, unless we have special conditions. Self-medicating without advice seems silly, so generally I’d suggest take note of authoritative advice (and not adverts or 2 for one deals) and if you have a condition you think needs treating then seek medical advice.

So i rather feel the article in Which? February magazine is approaching it in the wrong way. Rather than beginning with an extensive review of the pros and cons (some literally) of supplements. surely it should begin by warning that supplements are normally unnecessary if you eat a balanced diet. Seek medical advice before considering taking them to ensure you get the correct type in the correct dosage. It should also save you wasting your money.

I think that if Which? is involved in talking about health then perhaps it would be very fruitful to be on the side of angels and talk out about the pharma industry and its insidious drive to define “new” insufficiency levels.

And of course supporting AllTrials migh belatedly give some degree of respect to a consumer organisation unable to join with WHO and the BMJ and BUEC and 400 other organisations who have signed up to AllTrials. I am one of the 80.000 individuals who signed up over two years ago.

You have to admit it takes a brass neck to talk on health matters whilst ignoring one of the biggest campaigns to improve everyones health by making sure Pharma tests are properly reported rather than cherrypicked.

Anyway as per the first paragraph:
” The Journal of Medical Ethics carried a fascinating description, in June 2013, of an industry-supported medical-school lecture series on opioid prescribing for pain management, with questionable content, undeclared conflicts of interest and more. The course was only stopped after individuals in the medical school protested.19 Senior staff in medical institutions should remember that this kind of action, by junior staff, is risky, brave, and beneficial to patients.

June 2013 brought a remarkable article in JAMA Internal Medicine by a whistleblower, who had himself engaged in ‘disease-mongering’, not just in the academic literature, but also directly to the public, writing in everyday supermarket consumer magazines:

‘Low T’ (low testosterone level, aka hypogonadism) is high-profile these days. Sales of testosterone replacement therapies (TRTs) for Low T have more than doubled since 2006 and are expected to triple to $5 billion by 2017, according to forecasts by Global Industry Analysts. Driving these sales is a sophisticated marketing effort to define low testosterone level as a disease for which the treatment is TRT. I know this because, as a professional medical writer, I have helped craft that message for transmission in a range of media to both physicians and consumers.” Ben Goldacre 2013

I have taken vitamin c (2000mg) and cod liver oil for forty years with no ill effects. For the last few years I have added seaweed extract and Q10 and recently have added a vitamin B mitochondrial activator.
We are primates and along with all other apes and very few other animals are unable to synthesise ascorbic acid (vitamin C). We lost this ability in an evolutionary process long ago when our diet was extraordinarily rich in ascorbic acid. This vital vitamin is both water and air soluble and therefore only at its peak in foods when picked fresh. We cook a great deal out of our foods and throw it away (down the sink) in the water we boil our vegetables etc. This loss is also evident in the long transport and storage times of so called fresh fruit and vegetables. (the global supply chain)
The advice is always eat a balanced diet and I’m sure this is the ideal solution however in todays world this is almost impossible not least because of the pace of life but also because we do not trust the integrity of supermarket foods. Apples are grown half way round the world, irradiated and coated in a wax to make them look good. Also vegetables are grown using chemicals which we don’t trust and animals are factory farmed using antibiotics and cramped unnatural environments.
Our bodies are designed to process vast amounts of Ascorbic acid and expel excess through mainly filtering by the kidneys. Indeed I have felt well and have seen my urine to be clear and felt unwell and my urine to be very coloured. This means to me that the wellbeing of my inner self is not linked to my general wellbeing.
Ascorbic acid is taken up by the white bloods cells and is used to fight infection this lasts for about 4 to 6 hours so therefore if you do take supplementation take the time release variety.
I started taking vitamins after a consultant surgeon told me, as a hospital caterer, that I repaired the patients after he had cut them!
Finally that NHS experience 30 years ago provided another reason to look after myself in this way. The NHS is a wonderful emergency organisation and is to be treasured but it is adversely affected by the pharmaceutical companies. These companies do not have our health as their no. 1 interest. They have solutions and investments in our illnesses and the general public therefore take it upon themselves to find their own illness prevention strategies.

Another article that’s mostly accurate but contains some misleading information.

What’s not clear to consumers is what are EU approved health claims. There are lots of benefits of vitamins, minerals and nutrients that are true but are not allowed to be mentioned. Why? Because EU health claims are set up for general function. Information on health and reducing risk of disease are rejected despite the evidence being available.

Arthritis UK reviewed Omega 3 oils for arthritis because there is some evidence for it helping diseased joints. But no EU food health claim is permitted, so companies resort to adding Vitamin D to Omega 3 food supplements to be able to mention a benefit to joint mobility.

EU health claims are set up to protect Joe public from dodgy claims, that’s fine. But it doesn’t help those looking for natural products to improve their health. If you have a health problem, consult your health professional, only limitation is that some Doctors and Pharmacists have less knowledge of vitamins and nutrients.

Trust me, I’m a Pharmacist

Bryan Thomas says:
12 February 2016

Cod liver oil and malt as a lad made me what I
am today at 89!

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Here here,,,,,,,,,Me too,,,,,I can drink it right out the bottle……..Lovely stuff oil

In 1995 two doctor’s prescription medications sent me into a nervous breakdown which lasted almost 3 years. The depression and loss of taste associated with the breakdown have recurred with different depths and time periods almost every year since. However my research into supplements for Dementia has revealed SAMe and DHEA (both biochemicals which are already within your body and therefore which cannot be patented by the drug companies) to be excellent in the treatment of depression. Since starting to take both these supplemnts around June 2014 i have had no recurrence of either depression or loss of taste. I had been taking Prosac with marginal success, but having taken SAMe and DHEA for a few months I was able to discontinue Prosac completely in early 2015. I just wish that NICE and the NHS would realise that there is much value in some forms of Supplementary Medication.
We buy Swanson brand supplements from Health Monthly.

Unfortunately I didn’t see the article on vitamins – goodness knows why.
However how am I to make any decsion based on all these posts when they seem to contadict each other.
I take cod liver oil capsils (my mother used to hold my nose and pour it down my throat as a yougster!).
I tend to seldom get colds but when I run out of them I often catch a cold. Not scientific I know but it works for me.
I also take 400 iu of vitamin D. I cant tell if it does me any good but people tell me that it is a good idea to take it.
I also take 1500mg of 2KCL Glucosamine Sulphate and feel that this does my hips some good and my wife says that if she goes without it for three days then hips start to hurt.
Overall I feel that if things work for you then take them – if you cant tell the difference then forget them.
By the way I get my pills on line at a fraction the price of high street shops

Andrew says:
12 February 2016

Yet again I’m disappointed in a Which report on Vitamins etc that is based only on “expert” advice. Why does not Which try testing instead for once, as it does with other items?
Doctors and NHS Nutritionists are generally not trained at all in the beneficial effects of larger than RDA doses, and they are exposed to a great deal of negative comment and so called research sponsored by drug companies, who have a vested interest in undermining people taking nutritional supplements. (There are some doctors who buck this trend, and some who even specialise in helping people who don’t find that conventional medicine has very much to offer them e.g people with M.E.).
The broad theory behind larger doses is that people who are not in very good health may use up their stores of these nutrients in fighting what is wrong with them, so can need the extra supply to make up for this loss.
The assumption that all those who buy supplements are fools who have been taken in (by all the regular bursts of negative publicity?) is not credible.
Most people surely try these in hope, and only continue to take them if they feel a beneficial effect. It may be that some experience a “placebo” effect, but others are quite convinced by the results of taking supplements that they are well worth the cost, which is generally much lower than taking drugs.
I’ve yet to see any reliable published evidence of any systematic proven harm to those taking supplements, though I do not advocate taking doses that are known to be toxic. Compare this with the large number of people who have been damaged by the adverse effects of some drugs, and I think you may recognise that
supplements are not given a fair chance by the establishment.
I have personally taken very large doses of Vitamin C continually over about 40 years, with only beneficial results, and do not believe that Linus Pauling would be happy with the watered down approach now advocated by the institute bearing his name. If you take more Vitamin C than your body needs, then it simply causes loose bowel movements, which warn you to reduce the amount that you are taking.

Catherine Chetwynd says:
12 February 2016

In theory, it should be true that we don’t need supplements if we eat healthily. However, with supermarket fruit picked early and ripened in ripening rooms (oranges gain vitamin C on the tree, not in a room) and by force of their job, many people do not see daylight, leading to vitamin D deficiency, there are at least two reasons for taking vitamins – and I suspect many more.

chris says:
12 February 2016

I take 100mg of Magnesium on a daily basis
I have had an irregular heartbeat, but magnesium combined with a my prescribed medicines has kept the problem at bay.I know it works because if I forget the magnesium I get ectopic missed beats and this has happened several times to proof it is effective

Before taking calcium supplements, have your Vitamin D level checked. Many calcium deficiencies are actually caused by a deficiency in Vitamin D. Generally, the body produces its own Vitamin D by exposure to the sun; however, in the UK there is very little sunlight. Research has even correlated how much sun is necessary based on the country’s latitude. In the UK, this is probably more than most people get on a daily basis, hence the population’s regular deficiency.

Having come from a more sunny clime, I was taking 1000iu/day as a supplement; after several months I had my GP test my Vitamin D level to make sure that I was not getting too much. Even with supplementation, I still had a deficiency. My physician suggested that we increase it to 2000iu/day and test again after a few months. It has since returned to the normal range. Everyone is different and you should check with your GP if there is a concern.