About half of UK adults take supplements at least once daily. And to be fair, some vitamins and minerals – like vitamin D in winter and folic acid for people hoping to get pregnant – are recommended by health bodies like the NHS.
But some experts say that not all of these are necessary, and some may even be harmful. The British Dietetic Association warns against “wasting your money” on supplements that have “no proven benefits at all”.
One study published in JAMA Network Open found that those who took multivitamin tablets had a 4% higher risk of early mortality than those who didn’t. And consuming more vitamin D than you really need could lead to too much calcium in your blood, which may affect your kidneys, heart, and brain.
Not only that, but vitamin D2 might actually weaken your immune system, even if vitamin D3 seems to strengthen it. And the NHS says there’s “little evidence that supplements such as vitamin C, echinacea or garlic prevent colds or help you get better more quickly”.
Here, we spoke to Dr Lucy Hooper, private GP and co-founder of Coyne Medical, about which supplements she thinks can be useful, and which ones might just lead to more expensive pee.
How can I tell if I actually need supplements?
Dr Hopper said there’s no one supplement she’d recommend for absolutely everyone. “Correcting vitamin deficiencies or using supplements that help with a specific goal can be really valuable, but that’s not the same as saying that if we all take a particular supplement, we’re going to live longer,” she stated.
The best option for your health is a supplement that you really need and will actually take, she added. That might include iron for people who have anaemia, vitamin B12 for those with a proven deficiency, and “definitely” folic acid before pregnancy.
If you want to work out whether you need to use supplements, “blood tests can be useful, such as checking iron or B12”.
“But some supplements don’t require blood testing, including folic acid before pregnancy or a standard dose of vitamin D during winter,” added the expert.
The doctor told us that some symptoms, like overwhelming fatigue, should be investigated in their own right as they might be related to an underlying condition.
Additionally, sometimes people use supplements to do a specific job, like psyllium husk for lowering cholesterol and creatine for muscle-building.
“These targeted uses are much more useful than taking a whole bag of supplements because they’ve been marketed by a longevity or wellness influencer,” the GP continued.
More broadly, Dr Hopper follows a “food first” approach to nutrition for many vitamins and minerals. Eating a variety of fruits, vegetables, and healthy fats gives you nutrients that supplements may miss, though sometimes, our bodies really can’t make or get enough by themselves or through our diets.
What are the most (and least) useful supplements, according to a doctor?
11 supplements a GP says can be useful
This is “an example where we often can’t get enough from food alone, and supplementation can be really helpful, especially in British winters, when there isn’t enough sunlight for our skin to make sufficient vitamin D,” Dr Hopper shared.
Adequate vitamin D helps to keep your calcium and phosphate levels where they should be, which is useful for your bones and muscles.
In the UK, adults should consider taking 10 micrograms, or 400 international units, of vitamin D a day in autumn and winter. Those with darker skin or who have limited sun exposure might benefit from year-round supplementation.
Per the GP, doctors also often recommend vitamin D for pregnant or breastfeeding women – though this isn’t typically an unusually high dose.
Vitamin B12 – which makes and repairs DNA, helps to produce red blood cells, and ensures a healthy nervous system – is a “great example of why we need to understand not just whether someone is deficient through blood testing, but also why they might be missing out,” Dr Hopper explained.
Sometimes the issue is dietary – vegans might be at greater risk of a vitamin B12 deficiency. Other cases might occur because someone doesn’t absorb vitamin B12 well, perhaps due to stomach conditions, age-related issues, or certain medications.
“The cause affects the form and dose of replacement someone needs. For some people, appropriately dosed oral treatment, including sublingual preparations taken under the tongue, can provide adequate replacement,” the expert informed us.
“Others need injections. Understanding the cause and monitoring the response are important when deciding how best to manage it.”
Our bodies can’t make iron, but we need it for healthy red blood cells and normal immune function. Therefore, we have to get it from either food, supplements, or both.
Iron deficiency might be caused by heavy periods, bowel conditions like coeliac disease, and even “chronic blood loss from an undiagnosed cancer”.
“We don’t want to keep replacing the iron while missing the diagnosis,” Dr Hopper stressed.
Psyllium husk is a kind of soluble fibre that makes a bulk-forming gel in your gut. Dr Hopper said she often suggests it for those with high LDL, or “bad”, cholesterol, as “at an appropriate dose, it can lower LDL cholesterol by roughly 8–10%. In a meta-analysis of trials, the median dose was approximately 10 grams daily”.
Still, she added, she’d never recommend it without encouraging more dietary fibre consumption too: “There are brilliant, inexpensive fibre-rich foods we can eat, such as oats, beans, lentils, fruit and vegetables.
“Different types of fibre have different effects, but these foods offer benefits beyond fibre alone.”
Taking folic acid before getting pregnant is “one of the clearest and strongest cases we have for supplementation. It reduces the risk of neural tube defects [in the foetus] such as spina bifida,” the GP commented.
The usual dose is about 400mg a day, though some people might need more. Ideally, the expert said, people should begin supplementing three months before getting pregnant. The NHS says it should be taken in the 12 weeks after conception, too.While it might not prevent sniffles outright, the popular supplement might slightly decrease the length of a cold, a meta-analysis showed.“It’s inexpensive and generally low-risk at ordinary doses,” Dr Hopper said (adults should aim for 40mg a day).
“But some people need to be cautious, especially those prone to iron overload, such as people with hereditary haemochromatosis, or those with certain types of kidney stone.”
Myo-inositol helps our cells respond to hormones like insulin. The GP said she sometimes recommends it for patients with PMOS, previously known as PCOS – a meta-analysis has shown that myo-inositol can improve the “metabolic profile” of those affected.
The doctor also said she sometimes suggests riboflavin, which keeps our blood cells, brain, skin, and digestive tract healthy, for those suffering from migraines.
She said it’s “used at 400 milligrams daily for migraine prevention, usually with several months needed to assess the benefit”.
Calcium helps our bones, teeth, heart, and blood work normally. Usually, Dr Hopper goes for a “food first” approach to getting enough calcium – foods high in the mineral include milk, cheese, green leafy veg, fortified soya milk, bread made with fortified flour, and bone-in fish like sardines and pilchards.
“Some people who struggle with dairy can tolerate hard cheese or fermented dairy such as kefir, which can be useful sources of calcium. There are also non-dairy sources, including calcium-fortified plant-based drinks,” she shared.
Some studies have linked calcium supplementation, rather than getting enough calcium from our diet, to a higher risk of heart conditions. But the evidence is mixed, said the doctor.
“For people with osteoporosis who aren’t getting enough calcium through their diet, we would still consider supplementation,” she said. “But adding large amounts of supplemental calcium when you can meet your needs through nutrition probably isn’t a sensible idea.”
I’ve used creatine, which contributes to adenosine triphosphate (ATP) production, thus helping our energy and the contraction of our muscles, for months now.
“Research suggests it can provide additional improvements in muscle strength and mass,” Dr Hopper weighed in. “But it needs to sit alongside adequate protein intake and sufficient muscle stimulation through resistance training. Without those things, it’s unlikely to have the same impact.”
Though they’ve been linked to a small leap in mortality risk in some studies, the GP said: “The COSMOS trials provided some really interesting data on multivitamins, showing small improvements in cognition and memory with regular use in older adults.”
She added: “It isn’t strong enough evidence to say that taking a multivitamin will prevent dementia, but it is enough to suggest that an inexpensive multivitamin may be a sensible step for some older adults.”
3 supplements a GP says might be useless
1) Supplements taken without a clear reason
Dr Hopper called these “the least useful” of the lot. You might have a vague sense that a supplement or vitamin will make you healthier, but if you have no real reason to take it, you’re better off saving your money.
Be especially aware of “those promising something that sounds a little too good to be true: balancing hormones, boosting immunity, or reversing ageing”, she said.
2) Vitamins and supplements with very high doses of ingredients
“I’m always cautious about very high doses. More isn’t always better,” Dr Hopper clarified.
Sometimes, that can just lead to more expensive pee. But “excessive vitamin B6, for instance, can cause nerve symptoms and damage,” the expert added.
“It’s something I see surprisingly often nowadays, because people are taking multiple supplements, each containing high doses of the same vitamin. The combined dose can be much higher than they realise.”
3) Those with very low doses of the vitamin or mineral
On the flip side, we shouldn’t be fooled by what the GP calls “ingredient sprinkling”.
This “can make expensive supplements look impressive without supplying the dose shown to help in the research,” she said.
“Look at the full daily dose, rather than just whether a clinically studied ingredient appears on the packaging.”
Overall, Dr Hopper ended: “Be careful about where you spend your money, time and energy on supplements and apps, and consider whether they’re really giving you the care you need.
“I recommend supplements to my patients every day, so I’m not against taking them. But ideally, you should have a clear reason for taking them, understand what they can realistically do to help, and have a plan to review what’s working best for your health.”