Vitamin A is needed for normal vision, especially in low light, and it contributes to the maintenance of normal skin and mucous membranes, to the normal function of the immune system and to normal iron metabolism. It also has a role in cell specialisation, the process by which cells take on their specific tasks. Adults need about 700 µg (women) to 850 µg (men) a day, which a varied diet with colourful vegetables usually provides. Preformed vitamin A (retinol) can be harmful in excess, so adults should stay below 3,000 µg a day, and pregnant women need particular care.
Key facts about vitamin A
- Reference intake (D-A-CH, 2020): 700 µg a day for women and 800 to 850 µg for men, depending on age; 800 µg in pregnancy and 1,300 µg while breastfeeding. EFSA sets 650 µg for women and 750 µg for men.
- The nutrient reference value (NRV) printed on EU and Swiss labels is 800 µg.
- Safe upper level (EFSA, 2024): 3,000 µg of preformed vitamin A (retinol and retinyl esters) a day for adults, including during pregnancy. Beta-carotene from food does not count towards it.
- Two forms: preformed vitamin A from animal foods (liver, butter, eggs, cheese) and provitamin A carotenoids, mainly beta-carotene, from plants.
- Top sources per 100 g: beef liver about 8,000 µg, sweet potato about 960 µg, carrots about 830 µg, cooked spinach about 520 µg.
What does vitamin A do for the body?
Vitamin A is a group of fat-soluble compounds: retinol, retinal, retinoic acid and retinyl esters. Each form has its own job. Retinal is part of the light-sensitive pigment in the eye, and retinoic acid acts like a hormone that switches genes on and off in almost every tissue. In the EU and Switzerland, the following health claims are authorised. Vitamin A contributes to:
- the maintenance of normal vision;
- the maintenance of normal skin;
- the maintenance of normal mucous membranes;
- the normal function of the immune system;
- normal iron metabolism;
- and it has a role in the process of cell specialisation.
These six authorised claims cover the benefits of vitamin A that are well established. The sections below explain each one in plain terms.
7 key benefits of vitamin A
1. Vision in low light
In the retina, retinal combines with the protein opsin to form rhodopsin, the pigment that lets your eyes register dim light. Without enough vitamin A, rhodopsin cannot be rebuilt quickly, and one of the first signs of deficiency is night blindness: difficulty seeing at dusk or adjusting to the dark.
2. The surface of the eye
Vitamin A keeps the cornea and the conjunctiva moist and intact. Severe, long-lasting deficiency dries out the eye (xerophthalmia) and can damage the cornea. According to the WHO, vitamin A deficiency is the leading cause of preventable blindness in children worldwide; in Switzerland, it is rare.
3. Skin
Skin cells renew themselves constantly, and vitamin A guides how new cells mature. This is why vitamin A contributes to the maintenance of normal skin, and why retinoids (vitamin A derivatives) are used in skin creams and, under medical supervision, in acne medicines. A balanced intake from food is enough for normal skin; more vitamin A in tablets does not mean better skin. See our guide to the best vitamins for your skin.
4. Mucous membranes
The linings of the nose, throat, lungs, gut and urinary tract are mucous membranes, and they depend on vitamin A to form and renew. They are one of the body's first barriers against microbes from outside.
5. Immune system
Vitamin A contributes to the normal function of the immune system. Besides keeping the mucous membranes intact, it is needed for the development of several types of immune cells. In countries where deficiency is common, the WHO recommends vitamin A for children with measles, given under medical supervision. In well-nourished people, extra vitamin A does not add further protection. Read our overview of vitamins and minerals for a healthy immune system.
6. Iron metabolism
Vitamin A helps the body release iron from its stores and use it to make red blood cells, so low vitamin A can coexist with a form of anaemia even when iron intake is adequate. More on iron in the benefits of iron for women and men.
7. Cell specialisation, growth and reproduction
Retinoic acid tells cells which role to take on, which matters most where tissues grow quickly: in the embryo, in childhood and in tissue renewal. Vitamin A is therefore needed for normal growth and development before birth, which is also why both too little and too much can be a problem during pregnancy.
Retinol or beta-carotene: what is the difference?
Preformed vitamin A (retinol and retinyl esters) comes only from animal foods and fortified products. The body absorbs it well and stores the excess in the liver, which is why high intakes can build up. Beta-carotene and other provitamin A carotenoids come from orange, yellow and dark green plants. The body converts them into vitamin A only as needed, so beta-carotene from food does not cause vitamin A excess. As a rough guide, about 12 µg of beta-carotene from food provides 1 µg of vitamin A activity, which is why intakes are given as retinol activity equivalents (RAE).
If you eat a plant-based diet, all of your vitamin A comes from carotenoids. Absorption improves when you eat them with a little fat (a teaspoon of oil is enough) and when vegetables are cooked or chopped, for example carrots with olive oil.
Which foods are rich in vitamin A?
| Food | Vitamin A per 100 g (µg RAE, approx.) |
|---|---|
| Beef liver, cooked | 8,000 |
| Sweet potato, baked | 960 |
| Carrots, raw | 830 |
| Butter | 680 |
| Butternut squash, baked | 560 |
| Spinach, cooked | 520 |
| Dried apricots | 180 |
| Cantaloupe melon | 170 |
| Red pepper, raw | 160 |
| Egg, hard-boiled | 150 |
A single portion of liver can provide several times the daily need. A carrot (about 80 g) or a portion of sweet potato on its own covers most of it.
Can you take too much vitamin A?
Yes, but only preformed vitamin A. Very high doses at once cause headache, nausea and dizziness. Long-term intakes above the upper level can damage the liver, and studies have linked high retinol intake to lower bone density in older adults. The upper level of 3,000 µg a day applies to all preformed vitamin A from food and supplements combined.
Vitamin A in pregnancy
Too much preformed vitamin A in early pregnancy can harm the unborn child. Nutrition authorities such as the German Nutrition Society (DGE) therefore advise pregnant women to avoid liver, especially in the first trimester, and not to take high-dose retinol supplements without medical advice. Beta-carotene does not carry this risk. If you are pregnant or planning a pregnancy, check all your supplements with your doctor or midwife.
Smokers and beta-carotene supplements
Two large trials found more lung cancer in smokers who took 20 to 30 mg of beta-carotene a day, many times more than food provides. Smokers should not take high-dose beta-carotene supplements.
Vitamin A in Sanbera Daily Essential formulas
Daily Essential Women and Daily Essential Men each provide 200 µg of vitamin A from beta-carotene per daily serving of three tablets, 25 % of the NRV. It is a moderate, vegan contribution that adds to what you eat without approaching the upper level. Vitamin A contributes to the maintenance of normal skin and vision and to the normal function of the immune system. The same formulas contain vitamin D, which has different tasks; read what vitamin D really does. The Nightly Reload formulas contain no vitamin A.
Frequently asked questions
What is vitamin A good for?
Vitamin A is needed for seeing in dim light and contributes to the maintenance of normal vision, skin and mucous membranes, to the normal function of the immune system and to normal iron metabolism. It also has a role in cell specialisation, which matters for growth and for the development of the unborn child. Most people get enough from a varied diet with vegetables and dairy or eggs.
What are the signs of vitamin A deficiency?
The earliest typical sign is night blindness: trouble seeing at dusk. Later, the eyes and skin become dry and rough, and infections may become more frequent. A deficiency is rare in Switzerland; it mainly affects people with fat malabsorption, liver disease or a very restricted diet. Only a doctor can confirm it, usually with a blood test.
Are vitamins A and E good to take together?
They have different roles. Vitamin A contributes to the maintenance of normal vision and skin and to the normal function of the immune system, while vitamin E contributes to the protection of cells from oxidative stress. Both are fat-soluble and are absorbed best with a meal. A multivitamin with moderate amounts of both is fine for most people; avoid high doses of either. Read more about vitamin E benefits.
Is vitamin A an antioxidant?
Beta-carotene acts as an antioxidant in laboratory studies, which is why vitamin A is often listed with antioxidants. There is no authorised health claim for vitamin A or beta-carotene and protection of cells from oxidative stress, however. That claim belongs to vitamin E, vitamin C, vitamin B2, zinc and selenium.
Which vitamin A is safe during pregnancy?
Beta-carotene from vegetables and fruit is considered safe, because the body converts only what it needs. Preformed vitamin A (retinol) from liver and high-dose supplements should be limited, because excess can harm the unborn child. Pregnant women need slightly more vitamin A (800 µg a day), usually covered by diet. Discuss every supplement with your doctor or midwife.
Sources
- German Nutrition Society (DGE): Reference values for vitamin A
- EFSA Panel on Dietetic Products, Nutrition and Allergies (2015): Scientific opinion on dietary reference values for vitamin A
- EFSA Panel on Nutrition (2024): Scientific opinion on the tolerable upper intake level for preformed vitamin A and beta-carotene
- National Institutes of Health, Office of Dietary Supplements: Vitamin A and carotenoids, Health Professional Fact Sheet
- World Health Organization: Vitamin A deficiency
- European Commission: EU Register of nutrition and health claims
This article is for general information and does not replace advice from a doctor or pharmacist. Food supplements are not a substitute for a varied, balanced diet and a healthy lifestyle.