What Is Vitamin A Good For? UK Intake, Safe Limit and Pregnancy

Vitamin A contributes to the maintenance of normal vision, normal skin and normal mucous membranes, to normal iron metabolism and to the normal function of the immune system.¹ Adults need 700 µg a day (men) or 600 µg (women), and the NHS asks that food and supplements together stay at or under 1.5 mg (1,500 µg) a day.² Part of the Wellgard vitamins and minerals guide.

Evidence at a glance

• Studies: one pooled analysis of 12 fracture cohorts (292,655 people), three single cohorts, two randomised trials in adults, two Cochrane reviews in children and two other reviews.
• Largest single trial: 29,133 male smokers, beta-carotene 20 mg a day or none, five to eight years.³
• Strongest measured outcome: deaths 12% lower across 19 trials of 1,202,382 children, mostly in low- and middle-income countries (high-certainty evidence; not UK advice).⁴
• Not tested: no placebo-controlled trial has used fracture as its outcome.

Sources checked on 13 October 2026.

What does vitamin A do in the body?

Vitamin A has six authorised wordings in Great Britain, usable only when a serving supplies at least 15% of the 800 µg nutrient reference value (120 µg).^{1, 5} The NHS describes four of the roles in plainer words.²

How much vitamin A do you need, and what do RE and IU mean?

The NHS says a varied diet should supply the 700 or 600 µg, and because the body stores what it does not need straight away, you do not need it every day.² Labels use the 800 µg reference value instead, so "100% NRV" means 800 µg.⁵

Totals are given in µg of retinol equivalents (RE), which counts plant beta-carotene at the rate the body converts it.² Older and American labels use international units: 1 IU is 0.3 µg of retinol, so 10,000 IU is 3,000 µg.⁶ In the NHS's words, an average of 1.5 mg a day or less from diet and supplements combined "is unlikely to cause any harm".²

Which foods are highest in vitamin A, and are two eggs a day enough?

Liver and liver products such as pâté are "a particularly rich source", and the NHS says to eat them no more than once a week. Its other retinol sources are cheese, eggs, oily fish, fortified low-fat spreads, milk and yoghurt; beta-carotene comes from spinach, carrots, sweet potatoes, red peppers, mango, papaya and apricots.² Two eggs need not cover the day: eggs are one source of several, and the body stores vitamin A.²

How much vitamin A is too much?

The UK line is the NHS's 1.5 mg (1,500 µg) a day from food and supplements together: more than that on average "over many years may affect your bones", most of all in older people, especially women.²

That line rests on observational studies. In Swedish women, each extra 1 mg of retinol a day went with a 68% higher hip fracture risk.⁷ In 72,337 postmenopausal US nurses over 18 years, retinol at 2,000 µg or more a day carried 1.89 times the hip fracture risk of under 500 µg.⁸ In 2,322 Swedish men over 30 years, the highest blood retinol carried 2.47 times the hip fracture rate of the middle fifth.⁹ Pooled, high intakes carried 1.29 to 1.40 times the hip fracture risk, with no difference in total fractures.¹⁰

EFSA's upper level of 3,000 µg RE a day (June 2024) was set on birth defects and covers adults, including pregnant, breastfeeding and post-menopausal women.¹¹ It is an EU figure, not a UK limit.

Signs of excess come mostly from case reports: a 2026 review of 31 found headache and double vision in sudden excess, and liver, bone and muscle effects and raised blood calcium in long-term excess; treatment starts with stopping vitamin A.¹² If that sounds familiar, see a GP with your labels. Count every source: many multivitamins contain vitamin A and fish liver oils are high in it.² More in why fish oil is no longer recommended and how to choose a multivitamin for women.

Who should not take vitamin A supplements?

• Pregnancy. The NHS says not to take cod liver oil or supplements containing vitamin A (retinol) when pregnant: "Too much vitamin A can harm your baby's development. Always check the label."¹³
• Anyone eating liver every week: no supplements containing vitamin A, in the NHS's words.²
• Women after the menopause and older men "should avoid having more than 1.5mg of vitamin A a day from food and supplements".²
• Smokers, for beta-carotene. EFSA says smokers should avoid supplements containing it.¹¹ In 29,133 male smokers, 20 mg a day went with 18% more lung cancers; in 18,314 smokers, former smokers and asbestos workers, beta-carotene with retinol carried 1.28 times the lung cancer risk, and that trial stopped 21 months early.^{3, 14}
• Children, beyond the recommended drops. The government recommends daily vitamins A, C and D from 6 months to 5 years; the NHS says not to add cod liver oil, which also contains vitamins A and D.¹⁵ See babies and children.

Retinol or beta-carotene: what is the difference?

Retinol is preformed vitamin A from animal foods and many supplements; beta-carotene is a plant pigment the body converts into retinol, at a rate that varies with the food and the meal.^{2, 16} The NHS line covers total vitamin A. In the bone cohorts, the fracture association was with retinol, not beta-carotene.^{8, 10} EFSA set no upper level for beta-carotene, saw no sign of harm from it in the everyday diet, and says supplemental beta-carotene should be limited to meeting vitamin A needs.¹¹

Who in the UK runs low on vitamin A, and what are the signs?

The National Diet and Nutrition Survey for 2019 to 2023, counting food only, found 8% of women aged 19 to 64 (median 523 µg a day) and 18% of girls aged 11 to 18 below the lower reference nutrient intake. The survey changed method, so no trend can be read.¹⁷

Where deficiency is common, the eye shows it: in the Cochrane review of children, mostly in low- and middle-income countries, vitamin A lowered night blindness (risk ratio 0.32) and Bitot's spots on the eye (0.42), moderate-certainty evidence.⁴ Night vision also features in the signs of zinc deficiency.

What we don't know

• No randomised trial has tested whether staying under 1.5 mg a day changes fracture risk.
• Whether beta-carotene supplements carry any risk for people who have never smoked is unknown; the lung cancer trials enrolled smokers, former smokers and asbestos workers.
• EFSA could not say whether beta-carotene adds to the toxicity of preformed vitamin A.
• How much vitamin A UK adults get from supplements is not in the survey's food-only intake table.

Frequently asked questions

Is vitamin A the same as retinol?

Largely: the NHS says vitamin A is "also known as retinol", and beta-carotene counts once converted.² Retinol in a skin cream is a different use; the NHS intake figures cover what you eat and swallow.

Does vitamin A treat measles?

Not at home. In eight trials of 2,574 children with measles given vitamin A by clinicians with standard care, the pooled fall in deaths was not statistically significant (risk ratio 0.70); two doses on consecutive days went with fewer deaths in under-twos (0.18).¹⁸ The NHS says the MMRV or MMR vaccine is the best way to prevent measles.¹⁹

What should you not mix with vitamin A?

Other sources of vitamin A: a multivitamin, a fish liver oil and any formula listing vitamin A or retinol all count towards the NHS line with food.² Cod liver oil also carries vitamin D, which has its own ceiling; see can you take too much vitamin D.¹⁵

What blocks or depletes vitamin A?

For beta-carotene, absorption from plant foods ranged from 5% to 65% in human studies, shaped by the food and its processing, the fat and fibre in the meal, vitamin A status and gut health.¹⁶ Zinc contributes to normal metabolism of vitamin A; see what zinc is good for.¹

Sources

1. Retained Regulation (EU) No 432/2012, Annex: permitted health claims. Legislation. legislation.gov.uk.
2. NHS. Vitamin A. Page last reviewed 3 August 2020 (review overdue since 3 August 2023). nhs.uk.
3. ATBC Study Group. Randomised trial, 29,133 male smokers, 5 to 8 years. N Engl J Med, 1994. PubMed 8127329.
4. Imdad A, et al. Cochrane review, 47 trials, about 1.22 million children (deaths: 19 trials). 2022. PubMed 35294044.
5. Retained Regulation (EU) No 1169/2011, Annex XIII: nutrient reference values. Legislation. legislation.gov.uk.
6. Takahashi T. Report on food composition tables and vitamin A units, no participants. J Natl Cancer Inst, 1984. PubMed 6392674.
7. Melhus H, et al. Nested case-control study, 247 hip-fracture cases and 873 controls from 66,651 women. Ann Intern Med, 1998. PubMed 9841582.
8. Feskanich D, et al. Prospective cohort, 72,337 postmenopausal women, 18 years. JAMA, 2002. PubMed 11754708.
9. Michaëlsson K, et al. Prospective cohort, 2,322 men, 30 years. N Engl J Med, 2003. PubMed 12540641.
10. Wu AM, et al. Pooled analysis of 12 prospective cohorts: 8 on intake (283,930 people), 4 on blood retinol (8,725). J Bone Miner Res, 2014. PubMed 24700407.
11. EFSA NDA Panel. Upper intake level for preformed vitamin A and beta-carotene; opinion based on systematic reviews. EFSA Journal, June 2024. doi 10.2903/j.efsa.2024.8814.
12. Padmakar S. Systematic review of 31 reports, 26 single case reports. Clin Chim Acta, 2026. PubMed 42176931.
13. NHS. Pregnancy vitamins and supplements. Page last reviewed 3 June 2026. nhs.uk.
14. Omenn GS, et al. Randomised trial, 18,314 people at high lung-cancer risk, average 4 years. N Engl J Med, 1996. PubMed 8602180.
15. NHS. Vitamins for children. Page last reviewed 30 May 2024. nhs.uk.
16. Haskell MJ. Narrative review of human beta-carotene studies. Am J Clin Nutr, 2012. PubMed 23053560.
17. Office for Health Improvement and Disparities. National Diet and Nutrition Survey 2019 to 2023, table 5.27a. National survey, 863 women and 365 girls. Published 11 June 2025. gov.uk.
18. Huiming Y, et al. Cochrane review, 8 trials, 2,574 children (size from full text). 2005. PubMed 16235283.
19. NHS. Measles. Page last reviewed 31 July 2025. nhs.uk.

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