Which vitamins can help increase appetite?

Reviewed and updated: 4 September 2026

Which vitamins can help increase appetite? The honest answer is that no vitamin will make a well nourished person hungry, but a genuine shortfall of zinc, thiamine, vitamin B12 or iron can quietly blunt appetite, and correcting that shortfall often lets normal hunger return. That distinction matters more than any product, so I want to give you the full picture rather than sell you a bottle.

I am Dr. Miron, and this is one of the questions I get asked most gently and most often. Usually it is not the person themselves asking. It is a daughter worried her mum has stopped finishing meals, a parent whose child pushes the plate away, or someone recovering from a bug who simply cannot face food. In every one of those situations the useful answer is the same: work out why the appetite went, because that decides whether a nutrient has anything to do with it.

Which vitamins can help increase appetite: the short answer

Here is the whole guide compressed into a few lines, before we get into the detail.

• Zinc has the clearest link. Low zinc dulls taste and smell, and food you cannot taste is food you do not want. This is the one nutrient with real, if modest, trial evidence behind it.
• Thiamine (vitamin B1) matters when intake has been poor for a while. Loss of appetite is one of the recognised features of thiamine deficiency, which becomes a real risk in prolonged low intake, heavy alcohol use or after significant weight loss.
• Vitamin B12 and iron sit slightly further out. Neither reliably drives hunger, but both are common UK shortfalls, both contribute to the reduction of tiredness and fatigue, and exhaustion is one of the great appetite killers.
• None of them are appetite stimulants. If you are not short of a nutrient, taking more of it will not make you hungrier. That is the part most articles skip.
• Food comes first. Smaller, more frequent, nutrient dense meals do more for most people than any capsule.
• Persistent appetite loss is a medical question. If it has lasted weeks, or come with unintended weight loss, that is a GP conversation, not a supplement one.

What a low appetite actually is, and what usually causes it

Appetite is not a single switch. It is the sum of hormonal signals from your gut, blood sugar, sleep, mood, medication, activity level, and the plain sensory pleasure of food smelling and tasting good. Knock out any one of those and eating stops feeling like something you want to do.

In practice, the everyday causes I see come up again and again:

• Recovering from an infection, particularly anything that affected taste or smell.
• Stress, low mood, anxiety or grief, all of which suppress hunger signalling powerfully.
• Poor sleep, which shifts the balance of the hormones that regulate hunger and fullness.
• Medicines. A great many common prescriptions list reduced appetite as a side effect.
• Constipation or general gut discomfort, which makes the idea of another meal unappealing.
• Simply being out of the habit. Appetite is partly trained, and it fades when meals become irregular.
• Ageing, which has its own distinct physiology and gets its own section below.

Notice how few of those are nutritional. That is deliberate. If you take one thing from this guide, let it be that a supplement is the right answer for a minority of people asking this question, and being honest about that is more useful to you than an optimistic sales pitch.

Zinc, taste and smell: the strongest nutrient link to appetite

If there is a nutrient worth thinking about here, it is zinc. Zinc is involved in the enzymes that maintain the taste buds and the machinery of taste perception, and when zinc runs low, taste and smell can become dull, flat or distorted. Food stops being rewarding. People describe meals tasting of cardboard, or of nothing at all, and they stop bothering.

Because the loss of pleasure is the mechanism, restoring zinc in someone who is genuinely short of it can restore the pleasure, and appetite tends to follow rather than being pushed.

What the research actually shows

I want to be careful here, because this is exactly the point where supplement articles overreach. According to PubMed, a Cochrane systematic review of interventions for taste disturbances pooled nine trials of zinc supplementation and found that zinc improved overall taste acuity in people with zinc deficiency or idiopathic taste disorders, but graded that evidence as very low quality, and found the evidence insufficient to conclude on patient reported improvement (Kumbargere Nagraj et al., Cochrane Database of Systematic Reviews, 2017). So there is a real signal, and it is genuinely modest, and the reviewers themselves said so.

On appetite specifically rather than taste, a small randomised controlled trial gave 10 mg of zinc daily or placebo to preschool children over twelve weeks and reported improvements in calorie intake and in some eating behaviour subscales in the zinc group (Khademian et al., Pakistan Journal of Medical Sciences, 2014). Eighty children, one site, one population. Encouraging, not definitive, and not a reason for an adult to take zinc speculatively.

Zinc has also been examined alongside iron in the context of finicky appetite and low mood in children and adolescents, where a systematic review of randomised trials noted that iron and zinc deficiencies are common worldwide and are associated with poor memory, inattentiveness, finicky appetite and mood changes (Granero et al., Nutrients, 2021). Again the framing is about deficiency, not supplementation as a hunger lever.

Put together, that is a fair summary of the science: zinc status and appetite are connected through taste and smell, and correcting a deficiency is the mechanism that plausibly helps. It is not evidence that zinc increases appetite in people whose zinc is fine.

How much zinc, and where the ceiling sits

The UK reference nutrient intake for zinc is 9.5 mg a day for men and 7 mg a day for women, and most people eating a varied diet get there. Meat, shellfish, cheese, eggs, wholegrains, pulses, nuts and seeds are all good sources, and oysters are famously in a league of their own.

Supplemental zinc is where the caution belongs. NHS guidance is not to take more than 25 mg a day from supplements unless a doctor has advised it, and prolonged high dose zinc interferes with copper absorption, which is precisely why a well built zinc formula includes copper. That is also why our own zinc and copper tablets pair triple form zinc with copper glycinate rather than leaving zinc to run unopposed, and if you want the longer version of that argument we have written it up in zinc forms, why copper is added, and how much to take.

On the label wording, zinc contributes to normal macronutrient metabolism, to the normal metabolism of vitamin A, and to the maintenance of normal hair, skin and nails. Copper contributes to normal iron transport in the body. Those are the honest, permitted descriptions of what these minerals do, and you will notice none of them says anything about hunger, because nothing on the register does.

Thiamine and the wider B group

Thiamine, vitamin B1, is the B vitamin most directly tied to appetite in the clinical literature. Loss of appetite is one of the described features of thiamine deficiency, alongside dizziness, confusion and other symptoms, and clinicians are taught to look for it in people who have been eating poorly, drinking heavily, recovering from bariatric surgery, or experiencing prolonged vomiting (Wijnia, Journal of Clinical Medicine, 2022).

The uncomfortable logic there is circular, and worth spelling out. Thiamine has a short body store, measured in weeks rather than years. So someone who has been eating very little is at genuine risk of running low, and running low can further reduce appetite, which reduces intake further. That loop is real, and it is the strongest argument for not letting a period of poor eating simply run on.

For everyone else, the B vitamins are supporting cast rather than the lead. Thiamine contributes to normal energy-yielding metabolism. Vitamin B6 contributes to normal protein and glycogen metabolism. Riboflavin and niacin contribute to normal energy-yielding metabolism too. These are the reasons the B group is worth having covered when intake has dropped, not a promise that they will make you hungry. The UK reference nutrient intake for thiamine is 1.0 mg a day for men and 0.8 mg for women, which is a small number that a slice of fortified bread and a bowl of cereal will comfortably reach.

Vitamin B12 and iron: where low intake and tiredness overlap

Neither B12 nor iron is an appetite nutrient in the way zinc is. I include them because they are the two shortfalls most likely to be sitting underneath the question in a UK adult, and because both feed the exhaustion that makes cooking and eating feel like a chore.

Vitamin B12 contributes to normal energy-yielding metabolism and to the reduction of tiredness and fatigue. The UK reference nutrient intake is 1.5 micrograms a day, and the people who fall short are fairly predictable: those eating little or no animal food, adults over about fifty whose stomach acid has declined, people on long term metformin or proton pump inhibitors, and anyone with a malabsorption condition. If any of that describes you, our guide to who is most at risk of B12 deficiency is the better read.

Iron contributes to the reduction of tiredness and fatigue and to normal oxygen transport in the body. Iron deficiency remains the most common nutritional shortfall in the UK, and it falls hardest on menstruating women, teenagers and people eating plant based diets. Low iron and reduced appetite do travel together, especially in children, and the honest sequencing is to test rather than guess, because iron is one of the few nutrients where taking it unnecessarily is a bad idea. Our guide on how to increase ferritin covers the blood tests and what the numbers mean.

If tiredness rather than hunger is the thing actually bothering you, start with what vitamins help with tiredness instead, because that is a different question with a clearer answer.

The loop nobody warns you about: eating less makes eating harder

This is the part I most want people to understand, because it changes the urgency of the whole conversation.

When intake drops, the nutrients that support taste, energy metabolism and mood drop with it. Zinc thins out. Thiamine stores deplete within weeks. Iron and B12 fall more slowly but they fall. And every one of those shortfalls makes food less appealing, energy lower and mood flatter, which reduces intake further. It is a slow spiral rather than a cliff, which is exactly what makes it easy to miss.

That is the same territory as our main guide to what supplements to take while on a calorie deficit, which covers the nutrients that thin out when you deliberately eat less. If you are not eating enough by choice but because food simply does not appeal, the companion piece on what vitamin to take if you don't eat enough is closer to your situation. This guide is the narrower question sitting between the two: which nutrients are actually involved in appetite itself.

Food first, and what that means in practice

Before any supplement, these are the things that reliably move the needle, and they cost nothing.

• Shrink the portion, raise the density. A small plate of something rich beats a large plate that feels like a mountain. Full fat yoghurt, nut butters, cheese, olive oil, eggs, avocado.
• Eat by the clock, not by hunger. If the hunger signal is broken, waiting for it does not work. Small amounts at set times retrain the rhythm.
• Drink your calories when chewing feels like effort. Milk, milky coffee, smoothies, soups. Nourishing drinks are genuinely useful and often the easiest first win.
• Keep fluids away from mealtimes. Filling up on water just before eating leaves less room for food.
• Make food taste of something. If taste has dulled, lean on herbs, lemon, spice, salt and texture. Sharper flavours cut through better than bland ones.
• Move a little. A short walk before a meal genuinely helps for many people.
• Eat with someone. Company is one of the most underrated appetite tools there is, particularly for older adults living alone.

Appetite in older adults

Appetite decline with age is common enough that researchers gave it a name, and it deserves proper attention rather than being written off as normal ageing. The physiology behind it is genuinely different: gut hormone signalling shifts, the stomach empties more slowly, and fullness arrives earlier and lasts longer (Morley, Current Opinion in Clinical Nutrition and Metabolic Care, 2013).

More recent work has focused on the gut's nutrient sensing machinery, suggesting that the appetite suppressing hormone response to a meal is amplified in some older adults, which would mean the same food produces a stronger fullness signal than it once did (Dagbasi et al., Appetite, 2024). The authors are candid that a great deal remains unknown.

What that means practically is that no vitamin fixes this, because it is not primarily a nutrient problem. What helps is smaller and more frequent meals, protein spread through the day rather than loaded into one meal, treating dental problems and ill fitting dentures, reviewing medicines with a pharmacist, and eating in company. Covering the nutritional bases with something like a complete daily supplement routine is sensible insurance when intake is genuinely low, but it is the supporting act, not the answer.

Appetite in children, and when to involve a GP

Toddlers and young children have famously erratic appetites, and a child who eats almost nothing one day and clears the fridge the next is usually behaving entirely normally. Growth is the measure that matters, not any individual meal.

I would not give a child a zinc supplement on the strength of a fussy fortnight. The trial evidence discussed above used 10 mg a day under study conditions, and children have much lower upper limits than adults do. The right sequence is to talk to your GP or health visitor, who can check growth against the centile charts, look for the obvious things such as constipation or reflux, and decide whether any blood test is warranted.

Take a child to the GP promptly if reduced appetite comes with weight loss or faltering growth, ongoing tiredness or pallor, pain, vomiting, or a marked change in behaviour or mood.

What not to expect, and how long to give it

If you have identified a genuine shortfall and started correcting it, the honest timeline is weeks rather than days. Zinc related taste changes in the studies were assessed over roughly one to three months. Thiamine repletion can be quicker when the deficiency is real. Iron takes months to rebuild stores even once haemoglobin recovers.

What you should not expect is a hunger switch. Nothing on a supplement shelf does that, and anything marketed as though it does is either overpromising or is a medicine that belongs under a doctor's supervision. Prescription appetite stimulants exist, they are used in specific clinical situations under medical supervision, and they are entirely outside what a food supplement is or should pretend to be.

Safe upper limits worth knowing

If you are going to supplement, these are the ceilings to keep in view.

• Zinc. NHS guidance is to stay at or below 25 mg a day from supplements unless advised otherwise. Sustained higher intakes can lower copper status and, at high enough doses, cause nausea and gut upset.
• Iron. Taking 17 mg or less a day from supplements is unlikely to cause harm in most adults. Higher doses need a reason and ideally a blood test behind them, since iron overload is a real risk in some people.
• Vitamin B6. The long standing UK guidance level for supplemental B6 is 10 mg a day, and the European Food Safety Authority's 2023 review set a tolerable upper intake of 12 mg a day for adults. Prolonged high intakes are associated with nerve symptoms in the hands and feet.
• Vitamin A. Keep total intake from food and supplements at or below 1.5 mg a day, and avoid liver and retinol supplements in pregnancy.
• Vitamin B12, thiamine, riboflavin and niacinamide. Water soluble and generally well tolerated, though nicotinic acid at high doses causes flushing.

A few cautions worth knowing

• Zinc taken at the same time as certain antibiotics, including tetracyclines and quinolones, reduces absorption of the medicine. Separate them by a couple of hours.
• Zinc can interfere with penicillamine, and long term high dose zinc affects copper status.
• Iron reduces absorption of levothyroxine and some antibiotics, so it should be taken well apart from them.
• If you are pregnant or breastfeeding, take supplements only on advice, and avoid vitamin A supplements and liver.
• Zinc on an empty stomach causes nausea in a lot of people, which is unhelpful when the goal is to eat more. Take it with food.
• If you take regular medication, a quick word with your pharmacist is a genuinely worthwhile five minutes.

Red flags that need a doctor rather than a supplement

Please see your GP rather than reaching for a bottle if any of these apply.

• Appetite loss lasting more than a couple of weeks with no obvious explanation.
• Unintentional weight loss, particularly if clothes have become noticeably looser.
• Difficulty or pain on swallowing, persistent nausea, or vomiting.
• Persistent abdominal pain, a change in bowel habit, or blood in the stool.
• Appetite loss alongside low mood, hopelessness or withdrawal, which needs support in its own right.
• Appetite loss that started after a new medicine was introduced.
• Any appetite loss in an older adult who is also becoming frailer or falling.

None of that is meant to alarm you. It is simply that appetite is one of the body's more informative signals, and a supplement that masks a question is worth less than an answer.

How to choose, if you do decide to supplement

Assuming you have ruled out the medical questions and the shortfall looks plausible, here is what I would actually look at on a label.

• Elemental amount, not compound weight. "Zinc citrate 100 mg" is not 100 mg of zinc. Look for the elemental figure and the percentage of the nutrient reference value beside it.
• Copper alongside zinc if you intend to take zinc for more than a few weeks.
• A sensible dose rather than the biggest number. More is not better here, and 25 mg is the practical ceiling.
• A full ingredients list with no proprietary blends hiding the amounts.
• Purity testing you can ask about. Ours is tested for purity and heavy metals at our GMP-certified facility, and the formulas are formulated in the UK.

If you want the wider label reading skills, our guide to all our supplement guides collects the lot in one place, and the Pure Vitamins UK homepage will show you what we make.

Shop Zinc and Copper Tablets

Frequently asked questions

Which vitamin is best for increasing appetite?

Zinc has the most direct link, because low zinc dulls taste and smell and food that tastes of nothing is easy to leave. Thiamine matters when intake has been poor for weeks. But neither works as an appetite stimulant in someone whose levels are already fine.

Does vitamin B12 increase appetite?

Not directly. Vitamin B12 contributes to the reduction of tiredness and fatigue, and correcting a genuine deficiency often lifts energy enough that cooking and eating feel manageable again. If your B12 is normal, extra B12 will not make you hungrier.

How long does zinc take to affect taste and appetite?

In the trials, taste outcomes were typically assessed over one to three months rather than days. If nothing has changed after around eight to twelve weeks of a sensible dose, zinc was probably not the issue and it is worth going back to your GP.

Can taking too many vitamins reduce appetite?

Yes, in a couple of ways. High dose zinc commonly causes nausea, especially on an empty stomach, and iron supplements frequently cause constipation and gut discomfort, both of which make eating less appealing. Taking supplements with food and at sensible doses avoids most of this.

What can I give an elderly relative who has stopped eating much?

Start with small, frequent, energy dense foods and nourishing drinks, and eat with them if you can. Ask their pharmacist to review medicines and get dental problems checked. A daily multivitamin is reasonable insurance if intake is genuinely low, but persistent appetite loss with weight loss in an older adult should always be assessed by a GP.

Should I get a blood test before taking anything?

If the appetite loss has lasted more than a couple of weeks, yes. A GP can check full blood count, ferritin, B12 and folate, and often thyroid function, which between them explain a large share of unexplained appetite and energy problems. Testing before supplementing is particularly important for iron.

My honest bottom line

If someone asked me this question across a kitchen table, I would say: zinc is the one nutrient with a plausible mechanism and some genuine trial evidence behind it, thiamine matters once poor eating has gone on for a few weeks, and B12 and iron are worth checking because they are common and they drain the energy you need to want food. Beyond that, the honest work is in smaller and richer meals, better sleep, a medicines review, and company at the table. And if it has gone on for weeks, or weight is coming off without you trying, please make it a GP appointment rather than a shopping decision.

Dr. Miron, Founder of Pure Vitamins UK

Sources

• Kumbargere Nagraj S, George RP, Shetty N, Levenson D, Ferraiolo DM, Shrestha A. Interventions for managing taste disturbances. Cochrane Database of Systematic Reviews, 2017. https://doi.org/10.1002/14651858.CD010470.pub3
• Khademian M, Farhangpajouh N, Shahsanaee A, Bahreynian M, Mirshamsi M, Kelishadi R. Effects of zinc supplementation on subscales of anorexia in children: a randomized controlled trial. Pakistan Journal of Medical Sciences, 2014. https://doi.org/10.12669/pjms.306.6377
• Granero R, Pardo-Garrido A, Carpio-Toro IL, Ramírez-Coronel AA, Martínez-Suárez PC, Reivan-Ortiz GG. The role of iron and zinc in ADHD among children and adolescents: a systematic review of randomized clinical trials. Nutrients, 2021. https://doi.org/10.3390/nu13114059
• Wijnia JW. A clinician's view of Wernicke-Korsakoff syndrome. Journal of Clinical Medicine, 2022. https://doi.org/10.3390/jcm11226755
• Morley JE. Pathophysiology of the anorexia of aging. Current Opinion in Clinical Nutrition and Metabolic Care, 2013. https://doi.org/10.1097/MCO.0b013e328359efd7
• Dagbasi A, Fuller A, Hanyaloglu AC, Carroll B, McLaughlin J, Frost G, Holliday A. The role of nutrient sensing dysregulation in anorexia of ageing. Appetite, 2024. https://doi.org/10.1016/j.appet.2024.107718
• Study records located via PubMed. Intake and upper level figures follow NHS and UK reference nutrient intake guidance, and the European Food Safety Authority's 2023 tolerable upper intake review for vitamin B6.

Food supplements are not a substitute for a varied and balanced diet and a healthy lifestyle. This article is for information only and is not medical advice. If you have a health condition, take regular medication, or are pregnant or breastfeeding, speak to your GP or pharmacist before starting a supplement.