The global vitamin market is valued at almost $268 billion. Photo / 123RF
The global market in vitamin and mineral supplements is booming. Last year, it was valued at almost US$152billion ($268billion) and it is predicted to grow by just shy of 10 per cent each year between now and 2030.
It’s hardly surprising that we’re so keen on pill-popping. During the pandemic, a combination of research showing that vitamin D could help prevent some respiratory infections and studies showing a correlation between low vitamin D levels and adverse Covid outcomes meant vitamin D supplements were touted as a protection against or treatment for the virus.
Despite the fact that clinical trials have so far failed to conclusively confirm that vitamin D supplements could work in this way, the story lodged in the public consciousness.
Add to that a drip-feed of positive stories, such as the recently published study suggesting multivitamins could slow cognitive decline, and you can see why we might think that a daily dose of vitamins could act as some sort of health insurance policy.
Vitamins were first identified and isolated at the beginning of the 20th century when Casimir Funk, a biochemist investigating the incidence of beriberi in Asian populations, came up with the theory that it was caused by a lack of nutrients in their diet, rather than a toxin as had previously been thought. He also suggested that other diseases – such as scurvy and rickets – could fall into the same category. His theory was proven to be correct – beriberi is down to a lack of vitamin B – and the concept of vitamins that could prevent or treat illnesses was born.
By the 1920s and 1930s, the vitamin supplement was on the scene and has only grown in popularity. A 2018 Food Standards Agency report found that about half of UK adults took food supplements on a regular basis.
But while consumers may think they’re taking them for health reasons, most supplements in the UK are actually covered by the law that relates to food, not medicines. As such, unless they want to jump through very complicated licensing hoops, manufacturers can’t make any medical claims. That’s why you’ll see very careful wording such as “with vitamin C, zinc and selenium, which contribute to normal function of the immune system”, rather than “with vitamin C, zinc and selenium to boost your immune system”.
The fact is that many of those in the medical and scientific communities don’t necessarily believe that in developed societies – with ready access to a range of foods – our diets require this sort of supplementation. So, in short: is your daily multivitamin a waste of money?
We enlisted the help of Margaret Rayman, professor of nutritional medicine at the University of Surrey; British Dietetic Association spokeswoman Hannah Whittaker (bump2babynutrition.com); and public health nutritionist Dr Emma Derbyshire of the Health & Food Supplements Information Service (hsis.org). Here’s what they have to say…
Q: If I eat a well-balanced diet, could I still benefit from a multivitamin, or other individual supplements?
A: “If you eat a balanced diet, based on the Eatwell Guide – which includes protein-rich foods (meat, fish, eggs and pulses), whole grain carbohydrates, unsaturated fats, fruits and vegetables – then the evidence suggests that you will probably be getting the full complement of vitamins and minerals that your body requires,” says Whittaker. “The only nutritional supplement that you would need to take is vitamin D, as you can’t get enough through diet alone.” (The NHS recommends that all adults take 10 micrograms of vitamin D between October and early March in the UK.)
Q: What about suggestions that the food that we eat today is less nutritious?
A: That’s not strictly true. A 2017 review in the Journal of Food Composition and Analysis found conclusively that the mineral nutrient composition of vegetables, fruits and grains is not declining.
However, Derbyshire says that “despite thinking we are eating a well-balanced diet, many of us fall well short of the vital daily nutrients we need to fuel our bodies”, and claims that the Government’s National Diet Nutrition Survey (NDNS) shows that “we are lacking the essential nutrients we need”. But if you can’t do it through diet, she says that it makes sense to “bridge nutrient gaps” with a multivitamin and multi-mineral supplement.
Q: Is there a blood test I can have to confirm if I’m deficient in a particular nutrient?
A: All of our experts agreed that if you’re worried that you might be deficient in a vitamin or mineral, your first point of call should be your GP, not one of the many DIY tests on the market. Your GP can then run blood tests based on your symptoms.
Q: So, which groups do need to take a supplement?
A: If you’re pregnant or planning to become pregnant, it’s advised that you take a 400 microgram supplement of folic acid, as research shows that this reduces the risk of neural tube defects in babies. But you might not realise that your calcium needs also increase if you breast-feed.
“For adults over 18, the recommendation for calcium is 700mg daily, but in nursing mothers, it is 1,250mg,” says Whittaker.
Derbyshire adds: “Several studies have raised concerns about the potential nutritional inadequacy of vegetarian and vegan diets, with nutrients such as vitamin B12, vitamin D, iron, iodine, zinc, selenium, niacin, riboflavin and potassium placed on the watch list.”
Whittaker agrees. “If you’re excluding any food group – dairy, red meat, oily fish – from your diet, you may need a supplement.”
If you are following a vegan diet, Whittaker recommends taking a multivitamin that contains vitamin B12, iodine and choline, alongside vitamin D, and she points out that anyone who doesn’t eat oily fish should also be taking an omega 3 supplement if they are unable to obtain enough omega 3 through their plant-based diet.
Rayman says anyone who lives in the UK and doesn’t eat meat or fish should also consider a selenium supplement.
Q: Who else might need a supplement?
A: “As you get older, your stomach often atrophies, and its ability to produce hydrochloric acid diminishes,” says Rayman. “Hydrochloric acid is important for the absorption of vitamin B12, so older people may be deficient in this vitamin. The US Institute of Medicine actually recommends that people over the age of 50 should use a supplement or fortified foods to ensure that they’re getting enough B12.”
Other medications can also inhibit absorption of B12. “Metformin, often taken for diabetes, and antacids that are used to treat reflux and heartburn can also stop the body from absorbing vitamin B12, so check with your doctor if you’re prescribed any of these drugs, as they may suggest a blood test to ensure your B12 levels are adequate.”
Q: Can a multivitamin prevent deficiencies developing?
A: Yes – as has been proven with vitamin D, but all our experts were at pains to point out that so too can a healthy, balanced diet. “Studies show that supplements can help to boost vitamin and mineral intakes and that British adults who take supplements are more likely to meet nutrient recommendations than those who don’t,” says Derbyshire. “But supplements should be seen as a means to top up the regular diet – not to replace the role of food.”
Q: How can I find out the right dose of vitamins to take?
A: See a professional. “If a blood test shows that you’re deficient in a vitamin or mineral, you will usually be put on a short-term higher dose, known as a loading dose, before having your blood tested again,” says Whittaker.
“Then, assuming your levels had improved, you would be recommended a maintenance dose, usually in the form of a multivitamin and mineral supplement.”
Q: Could I overdose if I take more than the recommended amount?
A: For water-soluble vitamins, such as vitamin C, it’s impossible to overdose, as your body will excrete them. But for fat-soluble vitamins, such as vitamin D, which the body can’t easily excrete, taking a higher dose can mean levels build up in the body, which can be dangerous.
Q: How can I tell if a supplements brand is good quality or not?
A: “If it’s for sale in the UK, it has to pass stringent quality and safety tests,” says Whittaker. “Legally, if it doesn’t meet those requirements, it wouldn’t be on the shelves.”
Q: Are more expensive supplements better quality?
A: No. “There are a lot of people out there trying to make money out of supplements,” says Rayman. “And while there are some formulations of zinc and iron that are both more expensive to produce and easier for the body to absorb, buying a more expensive product doesn’t guarantee that you’re getting these formulations, and you can’t tell just by looking at the label.”
Q: Which type is better for maximum absorption: pill, capsule, spray or oil?
A: The format that a supplement takes generally depends on its natural form, so omega-3 oils will tend to come in a capsule or liquid, while pills are common for multivitamins and minerals.
Some supplement manufacturers may have conducted “bioavailability trials” to establish how much of the nutrient is absorbed, but more research is needed before we can categorically state that absorption from, say, sprays is better than just taking something in pill format.
“There are some patient groups for whom I might recommend a different format,” says Whittaker. “Older patients who have problems swallowing tablets can benefit from having a spray format. I have also seen parents with children with autism using a multivitamin patch with their child to help to ensure nutritional balance.”
Q: Have any vitamin or mineral supplements been proven to cut my risk of cancer, heart disease or dementia?
A: It’s hard to do large-scale trials into this over the time period needed to get a conclusive answer. “A lot of the diseases that we think of as being diseases of older people may start when we’re a lot younger,” says Rayman. “The plaques in arteries that contribute to heart disease may form from a very young age, even if you don’t have any heart problems until you’re older.
“Your fracture risk in your 70s could be related to your diet when you were laying down bone from your teens to your 30s.”
That said, Derbyshire points out that a very large study, which followed more than 22,000 men and women aged 39-79 for an average of 19 years, was published in the British Medical Journal and found a 26 per cent lower risk of dying from coronary heart disease (CHD) among the group taking omega-3 supplements compared with those who did not take supplements.
Vitamin D
This vitamin helps to regulate the amount of calcium and phosphate in the body. These nutrients are needed to keep bones, teeth and muscles healthy. It is known as the “sunshine vitamin” because the human body needs direct sunlight on the skin when outdoors to synthesise Vitamin D.
But in gloomy Britain, where supplies of sunlight are unreliable later in the year, the NHS recommends that everyone over four years old, including pregnant and breast-feeding women, should consider taking a daily supplement containing 10 micrograms of vitamin D during autumn and winter – that is, from October to March inclusive.
Vitamin B12
As we get older, our ability to absorb vitamin B12 (found in meat, fish, eggs and dairy products) from our diet diminishes. It is involved in helping the body to make red blood cells, in keeping our nervous systems healthy, and in helping our bodies to release energy from food. Lack of vitamin B12 can cause lack of energy and many of the symptoms of feeling “run down”, such as mouth ulcers and memory issues. The US Institute of Medicine recommends that people over 50 should use supplements to ensure they are getting enough B12, and the NHS suggests vegans should also monitor their levels of this vitamin.
Omega-3
Not a vitamin, as such, but a long-chain fatty acid that can help to keep the heart healthy. When doctors say that a normal diet supplies all the vitamins and minerals that we need, they assume that diet contains at least one portion (140g) of oily fish – meaning herring, pilchards, sardines, sprats, salmon, trout or mackerel, which provide omega-3. The NHS warns that pregnant women should not take fish liver oil supplements due to high levels of vitamin A.
Folic acid
The synthetic version of the vitamin folate, (vitamin B9). Folate helps the body make healthy red blood cells and is found in dark green leafy vegetables, beans, fruit and whole grains. If you’re pregnant or planning to become pregnant, you should take a 400 microgram supplement of folic acid, as this can reduce the risk of neural tube defects in babies. Avoid alcohol while taking folic acid, as it can stop the acid working well.
Dietary supplements
Anyone who excludes a major food group – such as dairy, red meat, oily fish or even leafy vegetables – from their regular diet for any reason should consider taking a supplement to compensate for the vitamins and minerals that they are missing.
What about dementia?
A lot of research is going on in this area, but more is needed. While many of the trials that equate supplements with better health outcomes – such as one that looked at multivitamins and dementia – are “promising”, they’re still relatively small in size and would need to be repeated in a far larger number of people before we can categorically state that everyone would benefit from a multivitamin.
New York Times: Tapping originated from a technique called Thought Field Therapy.