Vitamin A: food sources and safe limits

Do you need a vitamin A supplement?

Most people don't. The NHS says adults aged 19 to 64 need 700 µg of vitamin A a day (men) or 600 µg (women), and that you should be able to get all of it from a varied, balanced diet. Your body stores what it doesn't use straight away, so you don't need it every day.

UK intakes have slipped, though. In the latest National Diet and Nutrition Survey (NDNS), covering 2019 to 2023, adults aged 19 to 64 got an average of about 600 µg a day from food. One in ten had less than the lower reference nutrient intake (LRNI), an amount that is enough only for the small number of people with the lowest needs (13% of men and 8% of women). The survey changed how it records diets in 2019, so these figures don't line up neatly with older ones. A low intake in a survey isn't the same as deficiency either, which the World Health Organization says is rarely seen in high-income countries.

If your diet has little dairy, egg, oily fish or orange and dark green vegetables, food is still the first fix, because the richest sources are everyday foods. Supplements carry risks that food mostly doesn't, and the NHS gives four groups specific advice:

• If you're pregnant or trying for a baby, don't take cod liver oil or any supplement containing vitamin A (retinol), and avoid liver and liver products.
• If you eat liver or liver pâté every week, don't take any supplement containing vitamin A.
• If you smoke or have been heavily exposed to asbestos at work, don't take beta-carotene supplements, which have been found to increase the risk of lung cancer in these groups.
• Women past the menopause and older men, who are more at risk of osteoporosis, should keep their total from food and supplements to 1.5 mg a day or less.

What are the benefits of vitamin A?

Vitamin A is good for a few everyday jobs. According to the NHS, it helps your immune system work properly, helps you see in dim light, and keeps your skin and the lining of parts of the body, such as the nose, healthy. In Great Britain, the health claims allowed for vitamin A are set by law. Vitamin A contributes to:

• normal iron metabolism
• the maintenance of normal mucous membranes
• the maintenance of normal skin
• the maintenance of normal vision
• the normal function of the immune system

It also has a role in the process of cell specialisation. Those are the benefits of vitamin A that a product sold here is allowed to state, and they apply to vitamin A from food as much as from tablets. Claims that vitamin A supports hair, nails, bones, teeth or energy were assessed and not authorised.

Retinol and beta-carotene

Vitamin A reaches you in two forms. Retinol, sometimes called preformed vitamin A, comes from animal foods. Beta-carotene comes from plants, and the body turns it into vitamin A. The European Food Safety Authority (EFSA) notes that how much beta-carotene you absorb and convert depends on how much vitamin A you already have, and that no case of vitamin A poisoning from carotenoids alone has been reported. Eating a lot of beta-carotene can turn your skin orange, which EFSA describes as harmless and reversible.

What foods contain vitamin A?

Liver comes first by a long way, followed by orange and dark green vegetables, then cheese, eggs, milk, butter and oily fish. The figures below are from the UK's official food composition data (CoFID, Public Health England, 2021), which counts 6 µg of beta-carotene as 1 µg of vitamin A. Portions follow the British Dietetic Association (BDA), except liver pâté, where we've used 40 g. Figures are rounded.

A single portion of lamb's liver holds about 25 times a man's daily need and nearly 12 times the 1.5 mg limit, which is why the NHS advises eating liver or pâté no more than once a week. Fish liver oils are concentrated too: CoFID gives cod liver oil 18,000 µg per 100 g, so check the label of any capsule.

Sources of vitamin A if you don't eat meat or dairy

Plant foods give you beta-carotene rather than retinol, and a portion of boiled carrots, spinach or sweet potato covers a day's need on its own. The NHS also lists fortified low-fat spreads as a source.

How much vitamin A is too much?

The NHS says that an average of 1.5 mg (1,500 µg) a day or less from food and supplements combined is unlikely to cause harm, and that more than that over many years may affect your bones, making them more likely to fracture when you're older. Many multivitamins contain vitamin A, so count those too.

EFSA's upper level for preformed vitamin A, updated in 2024, is higher at 3,000 µg a day for adults, based on the risk to an unborn baby. The UK's lower figure comes from studies linking long-term intakes above 1,500 µg with hip fractures, a link earlier expert committees accepted they couldn't prove was cause and effect. UK advice stays at 1.5 mg, and it's the figure to follow here.

Reading the label: µg, IU and retinol equivalents

UK labels give vitamin A in micrograms, often as µg RE (retinol equivalents). Products from elsewhere may use international units (IU). For retinol, EFSA's conversion is 1 mg = 3,330 IU, so 1,000 IU is about 300 µg, and a "high strength" 10,000 IU tablet holds about 3,000 µg, twice the NHS limit on its own. Beta-carotene in IU can't be converted the same way. Our vitamin unit converter does the sums.

If a label lists retinol (or retinyl acetate or palmitate) and beta-carotene without saying how much of each, you can't tell the split. EFSA ran into the same problem when it surveyed products. The cautious approach is to count the whole amount towards your 1.5 mg.

Vitamin A tablets and capsules: what to check first

Most adults don't need either, and a tablet and a capsule follow the same rules, because the format doesn't change the vitamin A inside. Before you take one, check:

1. the form: retinol (often listed as retinyl acetate or palmitate) counts in full towards the 1.5 mg limit, while beta-carotene is handled differently, as the next section explains
2. the amount in one tablet or capsule, in µg or IU
3. the vitamin A in everything else you take, including multivitamins and fish liver oil
4. whether you fall into one of the groups above: pregnant or trying for a baby, eating liver or pâté every week, past the menopause or an older man, and, for beta-carotene, a smoker or someone exposed to asbestos

If your total from food and supplements stays at 1.5 mg a day or less, the NHS says it's unlikely to cause harm. If you're not sure, ask a pharmacist.

What is beta-carotene, and should you take a supplement?

Beta-carotene is an orange plant pigment that the body can turn into vitamin A. It is one of the carotenes, plant pigments such as beta-carotene and alpha-carotene that EFSA calls provitamin A carotenoids. EFSA counts 6 µg of beta-carotene as 1 µg of vitamin A, and 12 µg of other provitamin A carotenoids as 1 µg. The beta-carotene in food isn't a concern, because the NHS says there's no evidence it's harmful. A supplement is a different matter. EFSA's 2024 opinion says smokers should avoid supplements containing beta-carotene, that supplemental beta-carotene should mainly be assessed as a source of vitamin A, and that the data didn't allow an upper limit to be set. For everyone else, the NHS says not to take more than 7 mg of beta-carotene supplements a day unless a doctor advises it.

Beta-carotene supplements and smokers

The warning comes from two large trials. In the Finnish ATBC trial, 29,133 male smokers aged 50 to 69 took vitamin E, beta-carotene, both or a placebo for five to eight years. Those given beta-carotene had an 18% higher incidence of lung cancer, and the authors said the supplements might have harmful as well as beneficial effects. In the US CARET trial, 18,314 smokers, former smokers and people exposed to asbestos took 30 mg of beta-carotene with 25,000 IU of retinol a day. Their lung cancer risk was 28% higher than on placebo, and the trial was stopped about 21 months early. CARET combined the two nutrients, so it can't single out beta-carotene, but ATBC tested it on its own. Both trials were in high-risk groups, which is who the advice is aimed at.

Does vitamin A cause hair loss?

Too much can. A 2019 review of vitamins and hair loss in Dermatology and Therapy concludes that, as a general rule, too much vitamin A from food or supplements can cause hair loss. It describes case reports, including a woman on kidney dialysis taking a daily 5,000 IU supplement whose hair loss stopped a month after she gave it up. A small study it cites also found less hair in people taking isotretinoin, an acne medicine related to vitamin A.

Going the other way, there's no authorised claim that vitamin A supplements help hair, and a claim along those lines was turned down. Hair loss has many possible causes, so if yours is new or patchy, see your GP rather than adding a supplement. Our guide to biotin for hair and nails covers the other nutrient people most often reach for.

For how vitamin A fits with the rest of a supplement routine, see supplements to take together.

Where Natura fits

Natura's Daily Vitamin A (coming soon) is one capsule with 800 µg RE of vitamin A from algae beta-carotene and retinyl acetate. The label doesn't give the split, so count all 800 µg towards the NHS 1.5 mg: on top of an average UK diet of about 600 µg, that comes to about 1,400 µg. The same capsule is in the Vitamins Pack, and Daily Multi (also in packs such as the Core Pack) has another 800 µg of vitamin A, so don't combine any two of them, and don't take any of them if you're pregnant, eat liver weekly, smoke or have been exposed to asbestos. Vitamin A contributes to the maintenance of normal vision and normal skin; the single bottle sits with the daily bottles.