Vitamin A: effects, daily requirement & beta-carotene

Carrots are good for your eyes – every child knows this saying. It isn't wrong, but it tells only half the story. Because vitamin A comes to you in two completely different guises: as ready-made retinol from animal sources and as plant-based beta-carotene, which your body only converts as needed. And it's precisely this difference that decides how much you can take without worry.

Short and to the point: vitamin A contributes to the maintenance of normal vision, to a normal function of the immune system and to the maintenance of normal skin and mucous membranes. The daily requirement is around 0.8–1.0 mg retinol equivalent. Important: retinol can be stored and should be treated with caution in pregnancy – beta-carotene, by contrast, is regulated by the body itself.

The most important points in brief

• Vitamin A contributes to the maintenance of normal vision – plus immune system, skin, mucous membranes and iron metabolism.
• Retinol (animal) acts directly and can be stored; beta-carotene (plant-based) is only converted as needed.
• Daily requirement: around 0.8 mg (women) to 1.0 mg (men) retinol equivalent.
• In pregnancy, avoid high-dose retinol – beta-carotene is not affected by this.

What vitamin A does in the body

Vitamin A is an all-rounder that has a hand in very different places. In the retina of your eyes it is a building block of the visual pigment rhodopsin – the molecular switch that turns incoming light into a nerve signal. This is especially crucial for seeing in dim light. In skin and mucous membranes, vitamin A controls how cells mature and specialise; in this way it keeps functioning the barriers that separate the body's interior from the outside world. And in the immune system it is involved in the normal function of the defences.

Among the approved claims are that vitamin A contributes to the maintenance of normal vision, to a normal function of the immune system, to the maintenance of normal skin and mucous membranes, to a normal iron metabolism and to cell specialisation.

Retinol or beta-carotene – this is what you need to understand

Here lies the most important practical point of the whole topic. There are two ways to get vitamin A:

The clever part: with beta-carotene, your body is in the driver's seat. It only converts as much into vitamin A as it currently needs. That's why beta-carotene is considered the "safe" source, while with high-dose retinol you should keep an eye on the total amount.

Why many people keep a deliberate eye on vitamin A

Vitamin A is a classic of nutritional science, and certain diets make it sensible to keep an eye on it. Anyone who eats purely plant-based gets no ready-made retinol and is entirely dependent on the conversion of beta-carotene – background in the guide Nutrients for vegans. Vitamin A also regularly comes up around the topic of Nutrients for the eyes, as well as around Skin, hair & nails.

What research is investigating

The role of vitamin A for vision is textbook knowledge – the connection with the visual pigment rhodopsin is well understood biochemically and is the basis of the approved claim about vision. Equally well established is the function in cell specialisation and the barriers of skin and mucous membranes.

What remains exciting is the research around carotenoids as antioxidants: beta-carotene, lutein and zeaxanthin belong to the same family of substances, and science is investigating what role these plant pigments play for tissues such as the retina. For the eyes, the focus is more on lutein and zeaxanthin – details in the guide Lutein & zeaxanthin for the eyes. For vitamin A itself: the benefit of a good supply is clear, whereas high-dose supplementation "just in case" is not a sure thing because of its storability.

The classic with the carrots – what's true

Briefly on the famous carrot myth, because it comes up so often: it's true that vitamin A is needed for vision – especially in dim light – because it is a building block of the visual pigment rhodopsin. Anyone who really gets too little vitamin A can see less well in the dark. What isn't true is the reversal: even more carrots don't turn normal vision into "super-sight". The body covers its need, and the rest brings no linear bonus. Several nutrients are involved for the eyes anyway – besides vitamin A, above all lutein and zeaxanthin, as Nutrients for the eyes shows.

How much vitamin A a day – and the upper limit

The DGE gives for adults around 0.8 mg (women) to 1.0 mg (men) retinol equivalent per day. Through a balanced diet, the need is usually well covered. Because retinol is stored, there is an upper limit: the EFSA gives 3,000 µg retinol per day as the tolerable maximum amount. This limit does not apply to beta-carotene in the same way, because the body throttles the conversion itself.

Important: pregnancy & safety

One point deserves to be named clearly: during pregnancy, high-dose retinol is to be avoided – this also includes very liver-rich meals, because liver is extremely rich in retinol. This is a topic that absolutely belongs with medical guidance; blanket self-supplementation is out of place here. Anyone who is pregnant or planning to be will find orientation in the guide Nutrients when trying to conceive and in pregnancy. Beta-carotene is not affected by this restriction. In general: Can you take too many vitamins? answers the "more is better" question for all fat-soluble ones.

In practice: form, timing and combinations

For most people, the most relaxed strategy is to cover the need through beta-carotene from colourful vegetables – here the body regulates the conversion itself and an overdose is practically not an issue. Anyone who chooses a supplement often finds vitamin A as a component of a multivitamin, more rarely as a single preparation. As a fat-soluble vitamin, it belongs with a meal containing some fat. A sensible combination arises with zinc: zinc is involved in the transport of vitamin A, which is why both nutrients interact in metabolism. What remains important is keeping an eye on the total amount of ready-made retinol – especially when several supplements are combined, as the guide Combining several dietary supplements explains.

Who it's particularly worth a look for

Imagine two situations. You've been eating purely plant-based for a year and wonder whether your beta-carotene conversion is enough – then it's worth looking at colour-intensive vegetables and the guide Nutrients for vegans. Or you spend the day at the screen and think about your eyes – then vitamin A is one building block of several, as Nutrients for the eyes at the screen shows. In both cases: targeted rather than blanket, and keep an eye on the amount.

Food sources

Ready-made retinol is found above all in liver, butter, egg yolk and dairy products. Beta-carotene is provided by carrots, sweet potatoes, pumpkin, spinach and kale – often recognisable by the orange-yellow or deep green colour. A tip from the kitchen: because vitamin A and beta-carotene are fat-soluble, some fat with the meal (a splash of oil over the carrot salad) noticeably improves absorption. Lightly cooked vegetables also release their beta-carotene better than raw ones.

Honestly put into context

Vitamin A is an essential vitamin with clearly approved functions – with a good supply, much runs smoothly. At the same time, it is one of the few vitamins for which "more helps more" expressly does not apply: retinol is stored, has an upper limit and is delicate in pregnancy. The most relaxed route to a good supply leads via colourful vegetables and beta-carotene – here the body regulates itself.

Matching products from Scheunengut

You'll find vitamin A products in the Vitamin A category. Because vitamin A works in combination, it's also worth a look at Multivitamin and Lutein. Further reading: Nutrients for the eyes, Immune system: vitamin C, D & zinc, Skin, hair & nails, Lutein & zeaxanthin and the overview All 13 vitamins.

Frequently asked questions (FAQ)

What is vitamin A good for?

Vitamin A contributes to the maintenance of normal vision, to a normal function of the immune system, to the maintenance of normal skin and mucous membranes, to a normal iron metabolism and to cell specialisation. It is best known for its role in vision, especially in dim light.

What is the difference between retinol and beta-carotene?

Retinol is ready-made vitamin A from animal sources, acts directly and can be stored. Beta-carotene is the plant-based precursor: the body converts only as much as it needs. That's why beta-carotene is considered a safe source without a risk of overdose.

How much vitamin A do you need a day?

The DGE gives around 0.8 mg (women) to 1.0 mg (men) retinol equivalent per day. Through a balanced diet, the need is usually well covered. The tolerable upper limit for retinol is, according to the EFSA, 3,000 µg per day.

Is vitamin A dangerous in pregnancy?

High-dose retinol should be avoided in pregnancy, including very liver-rich meals. This belongs with medical guidance. Beta-carotene is not affected, because the body regulates the conversion itself. Clarify any supplement in pregnancy with a doctor beforehand.