Pick what you came here for. Each one opens with the things that mean you should see a doctor rather than a shelf, then the nutrients that hold a legally authorised EU claim for it, then the foods in our library that reach the threshold. Where nothing is authorised — sleep, most famously — we say so instead of inventing something.
Tiredness and low energy
Check this first
Fatigue that has lasted more than a few weeks deserves a blood test, not a supplement. Iron deficiency, an underactive thyroid, diabetes, sleep apnoea and depression all present as tiredness and all need a diagnosis. See a doctor first if you are also breathless, unusually pale, losing weight without trying, having very heavy periods, or feeling low most days.
Nine nutrients hold the authorised EU claim for reducing tiredness and fatigue. That claim is about nutrition, not about treating exhaustion: it applies to people whose intake is short, and topping up a nutrient you already have enough of does nothing.
The authorised wording
Each nutrient below carries the claim “… contributes to the reduction of tiredness and fatigue” under Regulation (EU) 432/2012. A food is listed here only if 100 g of it supplies at least 15% of the reference intake for one of them.
FolateIronMagnesiumNiacin (B3)Pantothenic acid (B5)Riboflavin (B2)Vitamin B12Vitamin B6Vitamin C
222 foods in the library qualify. The 24 richest per 100 g:
Loud snoring with pauses in breathing, gasping awake, or falling asleep during the day are signs of sleep apnoea, which supplements cannot touch and which raises cardiovascular risk. Insomnia lasting more than three months, or sleep problems alongside persistent low mood, should be seen by a doctor.
This is the honest one. No food and no vitamin or mineral holds an authorised EU claim about sleep. Not magnesium, not valerian, not chamomile, not tart cherry. Melatonin is the only substance with an authorised sleep claim, and only a narrow one: 1 mg close to bedtime for reducing the time it takes to fall asleep, and 0.5 mg for jet lag. Everything else marketed for sleep is selling you a story. What actually moves sleep is behavioural, and we have written about it.
What is actually authorised
“Melatonin contributes to the reduction of time taken to fall asleep” — 1 mg close to bedtime. “Melatonin contributes to the alleviation of subjective feelings of jet lag” — 0.5 mg on the first day of travel. That is the complete list. Melatonin is prescription-only in some countries, including for some preparations here, so ask your pharmacist.
Immune system
Check this first
Infections that keep coming back, need repeated antibiotics, or come with fevers, night sweats or weight loss are worth a doctor’s opinion rather than a supplement shelf.
Ten nutrients hold this claim. Note the word normal: the authorised wording is about an immune system working as it should when you are not short of the nutrient. Nothing here boosts immunity above normal, and no food prevents infection.
The authorised wording
Each nutrient below carries the claim “… contributes to the normal function of the immune system” under Regulation (EU) 432/2012. A food is listed here only if 100 g of it supplies at least 15% of the reference intake for one of them.
A fracture from a minor fall, losing height, or long-term steroid treatment are reasons to ask about a bone density scan.
Bone is built from more than calcium. Seven nutrients hold the bones claim, and protein holds it too. Weight-bearing exercise does more for adult bone than any of them.
The authorised wording
Each nutrient below carries the claim “… contributes to the maintenance of normal bones” under Regulation (EU) 432/2012. A food is listed here only if 100 g of it supplies at least 15% of the reference intake for one of them.
Muscle pain that started after a new medication, especially a statin, or dark-coloured urine after exercise, should be reported to a doctor or pharmacist promptly.
Four nutrients hold the muscle function claim, and protein holds the separate claim for maintaining muscle mass. None of them substitute for training.
The authorised wording
Each nutrient below carries the claim “… contributes to normal muscle function” under Regulation (EU) 432/2012. A food is listed here only if 100 g of it supplies at least 15% of the reference intake for one of them.
CalciumMagnesiumPotassiumVitamin D
163 foods in the library qualify. The 24 richest per 100 g:
If you have felt low, flat or hopeless most days for two weeks or more, or you have lost interest in things you used to enjoy, that is worth talking to a doctor about. It is common, it is treatable, and no amount of diet change substitutes for that conversation. If you are having thoughts of harming yourself, please contact your doctor or, in Cyprus, the mental health helpline on 1416.
These nutrients hold authorised claims for normal psychological function, normal cognitive function, or the normal functioning of the nervous system. Read that carefully: they are claims about keeping normal function normal. Not one of them is authorised as a treatment for low mood, anxiety or poor concentration, and we will not present them that way.
The authorised wording
Each nutrient below carries the claim “… contributes to normal psychological function” under Regulation (EU) 432/2012. A food is listed here only if 100 g of it supplies at least 15% of the reference intake for one of them.
Seven nutrients hold this claim. Worth knowing: high-dose antioxidant supplements have repeatedly failed to show the benefits that antioxidant-rich food is associated with, and some trials found harm. The claim below is about the nutrient in a normal diet.
The authorised wording
Each nutrient below carries the claim “… contributes to the protection of cells from oxidative stress” under Regulation (EU) 432/2012. A food is listed here only if 100 g of it supplies at least 15% of the reference intake for one of them.
Never take potassium supplements alongside an ACE inhibitor, an ARB (medicines ending in -pril or -sartan), or spironolactone, and never if you have kidney disease — the combination can raise blood potassium to dangerous levels. Food potassium is fine for most people, but ask your pharmacist if you are on any of those. And never stop or reduce blood pressure medication on your own.
Potassium is the only nutrient holding this claim. Eating potassium-rich food is not the same as taking potassium supplements, and the difference matters more here than anywhere else on this site.
The authorised wording
Each nutrient below carries the claim “… contributes to the maintenance of normal blood pressure” under Regulation (EU) 432/2012. A food is listed here only if 100 g of it supplies at least 15% of the reference intake for one of them.
Potassium
138 foods in the library qualify. The 24 richest per 100 g:
Sudden or patchy hair loss, a mole that is changing, or a rash that is spreading should be looked at rather than supplemented.
These hold authorised claims for normal skin, hair or nails. Biotin in particular is sold hard for hair growth: the authorised claim is about maintaining normal hair, and there is no good evidence it grows hair in people who are not deficient, which is almost everyone.
The authorised wording
Each nutrient below carries the claim “… contributes to the maintenance of normal skin” under Regulation (EU) 432/2012. A food is listed here only if 100 g of it supplies at least 15% of the reference intake for one of them.
Biotin (B7)Niacin (B3)Riboflavin (B2)Vitamin AZincSeleniumVitamin C
193 foods in the library qualify. The 24 richest per 100 g:
If you take levothyroxine, do not start iodine or selenium supplements without asking, and keep supplements well away from your dose. Unexplained weight change, a lump in the neck, or a persistently racing or slow pulse need a blood test.
Iodine and selenium hold the authorised claims here. Both have a genuinely narrow safe range — too much iodine causes thyroid problems just as too little does.
The authorised wording
Each nutrient below carries the claim “… contributes to normal thyroid function” under Regulation (EU) 432/2012. A food is listed here only if 100 g of it supplies at least 15% of the reference intake for one of them.
IodineSelenium
78 foods in the library qualify. The 24 richest per 100 g: