Vitamins A, B, C, D, E and K: Food Sources & UK Amounts

Most people meet the vitamins A, B, C, D, E and K somewhere around Year 8 biology, forget the details within a fortnight, and never think about them again until something prompts the question. A blood test. A tired stretch that won't lift. Or, very often, a change in how much you're eating.

That last one is why this question lands in our inbox so regularly. When your appetite drops and your portions shrink, the arithmetic changes. You're still getting the same six vitamins from the same foods, but there's less food.

What vitamins A, B, C, D, E and K each do

Six letters, but not six vitamins. B is a family of eight, which is why the alphabet skips from B to C and then jumps to D. The other five stand alone.

The split that matters most in practice is solubility. Vitamins A, D, E and K dissolve in fat, so your body can tuck away what it doesn't need today and draw on it later. The NHS notes that any vitamin A you don't use immediately is stored for future use, which is why a day without carrots is not a crisis. Vitamin C and most of the B vitamins behave differently. They aren't stored in any meaningful quantity, so a gap shows up faster.

Here's the whole set in one place, with the official UK amounts for adults aged 19 to 64.

Two things jump out of that table. The amounts are tiny, measured in milligrams and micrograms rather than grams. And the food sources overlap heavily. Eggs turn up under A, B and D. Oily fish under A and D. Leafy greens under B, C and K. You don't need six separate strategies.

Vitamin A: vision, immunity, and the liver rule

Vitamin A does three jobs the NHS lists plainly: it helps your immune system work properly, it helps vision in dim light, and it keeps skin and the lining of parts of the body such as the nose healthy.

You get it two ways. Retinol comes ready-made from animal foods, mainly cheese, eggs, oily fish, milk and yoghurt. Beta-carotene comes from plants and your body converts it as needed. That's the orange and dark green produce: carrots, sweet potatoes, spinach, red peppers, mango, apricots.

Then there's liver, which comes with its own rule.

Liver and liver pâté are extraordinarily rich sources. So rich that the NHS advises not eating them more than once a week, and if you eat liver weekly, not taking any supplement containing vitamin A at all, including fish liver oil. If you're pregnant, the guidance is to avoid liver and liver products entirely.

The B vitamins: eight jobs, almost no storage

The B group is where most people's mental map goes fuzzy, and understandably. There are eight of them, the numbering has gaps, and several go by two names.

They divide roughly into two camps. Thiamin, riboflavin, niacin and pantothenic acid are the energy-release crew: they help your body break down food and turn it into usable fuel. B6, folate and B12 are more involved in blood and nerves, forming haemoglobin, making red blood cells, keeping the nervous system working.

Almost none of them can be stored. The NHS says thiamin, riboflavin, niacin, pantothenic acid and folate all need to come from your diet regularly, which is the practical reason B vitamins show up in so many everyday foods rather than being something you top up occasionally.

Riboflavin has a quirk. UV light can destroy it, which is why the NHS says milk, eggs, fortified cereals, mushrooms and plain yoghurt should ideally be kept out of direct sunlight. Doorstep deliveries left standing in the sun are the obvious case.

Vitamin B12 is the one to watch on a plant-based diet. It isn't found naturally in fruit, vegetables or grains, so vegans may not get enough of it without fortified foods or a supplement.

And folate carries a separate instruction that has nothing to do with your daily 200 micrograms. If you're pregnant, trying for a baby, or could become pregnant, the recommendation is a 400 microgram folic acid supplement every day until you're 12 weeks pregnant. It needs to start before conception, which is the part people miss. Some women whose pregnancies are at increased risk of a neural tube defect are advised to take a higher 5mg dose instead, which is a conversation to have with a doctor first.

Vitamin C: why the UK figure is only 40mg

Ask most people how much vitamin C they need and you'll hear a number in the hundreds. The UK figure is 40mg a day for adults aged 19 to 64. A medium orange or a modest serving of peppers clears it.

That number sits lower than in several other countries, and it reflects what's needed to keep the body's stores topped up rather than what a supplement manufacturer might suggest. Vitamin C protects cells, maintains skin, blood vessels, bones and cartilage, and helps wounds heal. A serious shortfall causes scurvy, which is rare in the UK but not extinct.

You can't store it, so it needs to come in regularly. Good sources are citrus fruit and orange juice, peppers, strawberries, blackcurrants, broccoli, brussels sprouts and potatoes. Potatoes surprise people. They aren't concentrated in vitamin C, but the portions are generous enough to contribute meaningfully.

Above 1,000mg a day, vitamin C starts causing stomach pain, diarrhoea and flatulence. Unpleasant rather than dangerous, and it settles once you stop.

Vitamin D: the one you can't eat your way to

Vitamin D is the exception to everything above. It's also the only one where UK government advice tells healthy adults to take a supplement.

It regulates calcium and phosphate, which keeps bones, teeth and muscles healthy. A shortage causes rickets in children and osteomalacia, a painful softening of the bones, in adults. All straightforward so far. The complication is supply.

From late March or early April to the end of September, most people in the UK make all the vitamin D they need from sunlight on their skin. Between October and early March, we don't. The sun sits too low for the necessary wavelengths to reach us. And vitamin D appears in only a handful of foods: oily fish such as salmon, sardines, trout, herring or mackerel, red meat, egg yolks, liver, and fortified spreads and breakfast cereals. British cows' milk isn't fortified, unlike in some other countries, so it doesn't help much here.

That combination is why UK government advice is different for this one vitamin. Everyone should consider taking a daily 10 microgram supplement during autumn and winter, including pregnant and breastfeeding women. Some people are advised to take it all year round: anyone not often outdoors, anyone living in a care home, anyone who usually covers most of their skin outdoors, and people with African, African-Caribbean or South Asian backgrounds, who make less vitamin D from the same sunlight.

The survey data backs up why the advice exists. In the National Diet and Nutrition Survey covering 2019 to 2023, published in June 2025, 18% of adults aged 19 to 64 had low vitamin D status, meaning a blood concentration below 25 nanomoles per litre. The seasonal pattern is stark. Across age and sex groups aged 11 and over, the proportion below that threshold ranged from 21% to 38% in January to March, and from 0% to 10% in July to September.

There is an upper limit here too. Don't take more than 100 micrograms (4,000 IU) a day. Too much vitamin D over a long period causes calcium to build up in the body, which weakens bones and can damage the kidneys and heart. For most people, 10 micrograms is enough.

Vitamin E and vitamin K: the quiet pair

These two rarely get a look-in, partly because shortfalls are uncommon on a normal UK diet.

Vitamin E helps maintain healthy skin and eyes and strengthens the immune system. Adults need 4mg a day for men and 3mg for women, which is easily covered by plant oils such as rapeseed, sunflower, soya, corn and olive oil, plus nuts, seeds and wheatgerm. Since it's fat-soluble, your body stores the surplus, so you don't need it every day. Supplements at 540mg (800 IU) or less a day are unlikely to cause harm.

Vitamin K is a group of compounds your body needs for blood clotting and wound healing, with some evidence it also supports bone health. Its requirement is the only one expressed relative to your size: roughly 1 microgram per kilogram of body weight per day. Someone weighing 65kg needs about 65 micrograms; someone weighing 75kg needs about 75. Green leafy vegetables such as broccoli and spinach are the main sources, along with vegetable oils and cereal grains, with smaller amounts in meat and dairy. Any surplus is stored in the liver.

One practical note. If you take warfarin, vitamin K intake affects how the medicine works, so keep your leafy green intake reasonably steady rather than swinging between none and a lot, and talk to whoever manages your anticoagulation before starting a supplement.

What changes when you're eating less

This is the part that changes what you do at the supermarket.

Vitamin requirements don't scale down with your appetite. Drop from 2,200 calories a day to 1,400 and you still need the same 40mg of vitamin C, the same 200 micrograms of folate, the same 1.5 micrograms of B12. What changes is the density you need from every mouthful. Smaller plates have to work harder.

This applies to anyone in a sustained calorie deficit, and it applies with extra force if you're on a GLP-1 medication such as Mounjaro or Wegovy. These treatments reduce appetite substantially, which is the point, but a much smaller intake makes food choices matter more than they did before. Our guide to what to eat on Mounjaro goes into the practical side of building meals when you're simply not that hungry.

The national picture shows how little slack there is to begin with. In the same 2019 to 2023 survey, fewer than one in five adults (17%) met the 5 A Day recommendation, with average intake sitting between 3.3 and 3.7 portions a day depending on age. Fruit and vegetables carry a large share of our vitamin C, folate, beta-carotene and vitamin K, so a diet already two portions short has very little margin left when the portions shrink further.

A few habits cover most of the ground without turning meals into a spreadsheet exercise. Keep dairy or a fortified alternative in the day for riboflavin, B12 and some vitamin A. Put a green vegetable on the plate most evenings for folate and vitamin K. Eat oily fish once or twice a week for vitamin A and D together. Cook with a plant oil rather than relying only on butter, which handles vitamin E. And keep some fruit or peppers in the rotation for vitamin C.

Protein deserves a mention too, since it tends to be the thing that slips first when portions shrink and it carries several B vitamins with it. Our list of high-protein, low-calorie foods is a useful place to start, and if you're on medication, protecting muscle while you lose weight covers why that matters beyond the vitamin question.

Do you need a supplement?

For most people eating varied meals, no. The NHS position is that a varied and balanced diet supplies what you need, with vitamin D in autumn and winter as the standing exception.

But there are situations where a supplement earns its place: a vegan diet without fortified foods, for B12. Pregnancy or planning one, for folic acid. Limited sun exposure, for year-round vitamin D. And a period of significantly reduced intake, where a straightforward multivitamin providing around 100% of the reference amounts is reasonable insurance rather than optimisation. We've written separately about what the evidence does and doesn't support for weight-loss supplements, and the same scepticism applies to high-dose vitamins.

What deserves more attention than it usually gets is the ceiling. These are the amounts the NHS identifies as unlikely to cause harm, or the points at which problems start.

Vitamin B6 catches people out more than the rest. It turns up in high doses in supplements marketed for energy or premenstrual symptoms, and at 200mg a day or more it can cause a loss of feeling in the arms and legs called peripheral neuropathy. That usually improves once you stop taking it, though in a few cases, particularly after months of large doses, the effect has been permanent.

Two rules cover most of the risk. Don't stack a multivitamin on top of individual supplements without adding up the totals, and if you eat liver weekly, skip vitamin A supplements altogether.

Spotting a shortfall

Symptoms are a blunt instrument here. Tiredness, low mood and dry skin have dozens of causes, and vitamin deficiency sits well down the list for most people. A lot of supplement marketing works by encouraging you to read an ordinary bad week as a nutritional emergency.

A few signs are more specific. Poor vision in dim light points towards vitamin A. Cracked corners of the mouth and a sore tongue are associated with riboflavin. Tiredness with unusual breathlessness can indicate the anaemia caused by low folate or B12. Bone or muscle pain, particularly through winter and particularly in someone with limited sun exposure, raises the question of vitamin D. Easy bruising and slow-clotting cuts can point to vitamin K.

None of these are diagnostic on their own. If a pattern persists for a few weeks, a GP appointment and a blood test will tell you far more than a symptom checker will, and it means any supplement you end up taking is aimed at something real.

This article is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional before starting any treatment.