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.”
