While a greater awareness of the power of vitamins, and a willingness to take them, is no doubt a good thing, some nutritionists think our reliance on pills is misplaced. Rather than shell out exorbitant amounts for a bottle that will last you a month, they argue that for most of us, we can get all the vitamins we need simply by eating better.
Here, then, is your guide to what you actually need to take, when to take it, and when to mix it up.
Do I really need to take daily vitamins every day?
We hate to break this to you, but fixating on your supplements stack might be money down the drain. When it comes to the efficacy of daily vitamins, there’s very little evidence that they’re doing you any good. “Supplements get marketed as an insurance policy, but the evidence doesn’t really back the idea that every healthy adult needs a daily multivitamin,” explains dietitian Sasha Watkins.
According to the British Nutrition Foundation, a varied and balanced diet should provide enough vitamins and minerals to meet most people’s needs, with the exception of vitamin D, which we mainly get from sunlight on skin.
Beyond that, a 2026 review of multivitamin research found that there is little evidence that routine multivitamin use has clinical benefits for generally healthy adults. The research found that there were no obvious decreases in cardiovascular disease and mortality rates in those regularly taking vitamins, and only limited evidence on cancer prevention. “The study authors recommended a targeted approach to supplementation,” explains Ro Huntriss, registered dietitian and chief nutrition officer at fitness app Simple Life. “That means identifying deficiencies, dietary restrictions, and higher-risk groups before recommending blanket daily use.”
As the British Dietetic Association notes, there’s no supplement that delivers the same benefits as a healthy balanced diet. “Vitamin supplements are not a get-out-of-jail card for a poor diet,” says Watkins. “If you’re eating a varied diet with enough protein, fruit, veg, wholegrains and healthy fats, you’re already covering most of the bases.”
Is there a best time to take vitamins?
Assuming you’ve addressed any dietary imbalances, your next step might be to consult a GP or dietitian if you still feel off. They might point to a discrepancy or lack of a certain vitamin in your diet, at which point they might prescribe or recommend you taking certain pills. As with all pills and medication, the best approach is consistency; taking them at the same time each day builds a habit, meaning you’ll be less likely to forget them.
If you’re taking fat-soluble vitamins (A, D, E & K), Huntriss suggests taking them with meals containing fats to improve absorption. On the other hand, water-soluble vitamins (B & C), don’t require food.
Should I vary my intake based on my fitness goals?
While most vitamin deficiencies can be addressed by switching up your food (honestly, have you tried eating vegetables? They’re great), there are occasions when supplemental support can be a huge help. As anyone who’s ever trained for a fitness event, or thrown themselves into a gym plan can attest, that stuff’s exhausting. Taken strategically, this is when vitamins can help.
When you’re building muscle
“Energy intake and protein tend to be the biggest drivers of overall success here,” says Huntriss. Micronutrients can support performance and recovery. Vitamin D is important for muscle function, particularly if its levels are low, and B vitamins support energy metabolism. It isn’t a magic bullet, though. A 2023 systematic review in athletes found benefits mainly where vitamin D levels were low to begin with, rather than from loading up on pills. And, again, don’t skip recovery, and protein. “Supplements may help fill the gap if your diet is inconsistent, but they cannot replace adequate training, calories, and protein,” says Huntriss.
When you can’t sleep
“If the issue is poor sleep, vitamins are rarely the primary solution unless there is an underlying deficiency,” says Huntriss. Assuming you’ve got your sleep hygiene locked in, it’s still worth exploring vitamins. Low vitamin D levels have been associated with poorer sleep quality in several studies, while magnesium has shown positive results on sleep quality.
When you’re training for a marathon
When you run consistently, your overall need for nutrients and fluids increases to support energy production, recovery, and hydration. “B vitamins contribute to energy metabolism, and vitamin C is essential for tissue repair,” says Huntriss, adding that electrolytes play an important role, too. Sodium becomes more important during longer runs due to heavy sweating. But again, Huntriss thinks you can probably get by with adjusting your diet, especially if you’re using “appropriate sports hydration strategies” in the form of electrolyte-fortified drinks.
“The one genuinely worth watching is iron,” adds Watkins. “Endurance running quietly depletes it, including through foot-strike haemolysis, where the repeated impact of landing damages red blood cells.” With iron key in ferrying oxygen to your muscles, your stamina takes the hit when stores run low. Red meat and iron-rich greens like spinach, chard, and water cress can help.
When you’re trying to conceive
Male fertility is having a moment, and the supplement industry has noticed. “A few nutrients come up repeatedly,” says Watkins. “Zinc is the headline one – found in meat, shellfish, nuts, seeds and wholegrains. Selenium contributes to normal sperm production too, with Brazil nuts, eggs, fish and shellfish among the best sources.” Watkins recommends reaching for a few Brazil nuts each day. Beyond that, she says “Excess weight, smoking, heavy drinking and chronic stress all drag on sperm quality more than any pill offsets. See a GP rather than self-prescribing a stack.”
What vitamins should I take every day?
Our experts are both of the opinion that a good diet supersedes the need to shell out at Holland & Barrett. “Ideally, any decision regarding supplements should be based on diet, lifestyle, and individual deficiency risks,” says Huntriss. That said, there are certain vitamins that can help us all from time to time.
A further word of warning first: “Taking too much of a vitamin or mineral can be dangerous, so don’t double up,” advises Watkins. In other words, If your multivitamin already contains vitamin D, don’t stack a separate one on top unless a health professional has told you to.
Vitamin D supports bone health, muscle function, and the immune system. “It’s especially relevant in the UK, because it’s difficult to get enough from food alone,” says Huntriss. Since we mainly rely on sunlight exposure to produce vitamin D in our skin, it’s hard to get enough of it during the colder, darker months. Ten 10 micrograms of Vitamin D3 (cholecalciferol) daily, with food, should be taken during winter.
Vitamin B12 is involved in red blood cell production, oxygen transport, and overall neurological function. People with a deficiency (hello, vegans) are more likely to feel fatigue and lower physical performance. “Cyanocobalamin is a well-studied and effective form,” advises Huntriss. It’s available as tablets, capsules, and sprays, so take your pick.
“Omega-3 isn’t a vitamin, but it belongs in any food-first conversation,” says Watkins. The simplest route is your plate: oily fish like salmon, mackerel and sardines eaten a couple of times a week. “If you rarely eat fish, a fish oil supplement is a reasonable gap-filler. “
Magnesium is involved in nervous system regulation, muscle function, and energy production. “UK intake data shows a decent slice of men fall short,” says Watkins. “This matters more and more as your training load rises.” Nuts, seeds, wholegrains and leafy greens are the food-first answer; a supplement is a backstop if your diet’s light on them.
Iron is essential for transporting oxygen, and assists with endurance performance. A deficiency can impact energy levels and reduce overall training capacity, particularly in women. “I recommend testing your iron levels before starting supplements,” says Huntriss. “Ferrous sulphate is commonly prescribed clinically, while Ferrous bisglycinate is often better tolerated. Ideally, the prescriptions should be guided by blood tests.”
