Vitamin A

What is vitamin A?

Vitamin A is an essential fat-soluble vitamin. You may recognise names such as retinol, retinal, retinoic acid or retinyl ester — these are all forms of vitamin A.

Some animal products have preformed vitamin A (also known as retinol). Some fruits and vegetables have plant pigments (provitamin-A carotenoids, which include beta-carotene) that are converted in the body to vitamin A.

Why is vitamin A important for my health?

Vitamin A helps to keep your body healthy. It maintains your immune system and protects important structures in the eye: the cornea, conjunctiva, photoreceptor rod and cone cells in the retina. This is why you may have heard that vitamin A is important for eye health.

Vitamin A also supports reproduction by keeping sperm healthy and helping the production of eggs.

What are natural sources of vitamin A?

Some foods high in vitamin A come from animals, such as meat (beef liver), full-fat dairy and egg yolks.

Beta-carotene, which is converted into vitamin A, is mostly found in the orange pigment in fruits and vegetables and in some oils.

The way you prepare your food affects how well vitamins are absorbed. For example, cutting up or cooking vitamin A-rich food will help you get the most out of it.

Should I take vitamin supplements?

The best way to give your body vitamins is to eat a varied diet that includes healthy proteins and plenty of fresh fruits and vegetables. Taking a vitamin supplement may mean you get that vitamin, but not enough other nutrients to help your body absorb it.

However, if you are on a restrictive diet (for example, a vegan diet) or have a health condition that impacts how you eat food or absorb nutrients, you may need to take vitamin supplements to avoid deficiency and stay healthy.

Before taking any vitamin supplement, speak with your doctor or an accredited dietitian.

What is the recommended dosage for vitamin A?

The recommended dietary intake (RDI) is determined by the Australian government and it varies depending on your life stage and gender. The RDI for vitamin A ranges from 250μg (micrograms) daily for infants 0 to 6 months of age, to 900μg daily for men and 700μg daily for women. Pregnant women and breastfeeding mothers should consult a dietitian for specific nutrition advice.

Can taking vitamin A supplements cause side effects?

Vitamin A is a fat-soluble vitamin, which means it gets stored in your body’s own cells. This means that if you have more vitamin A supplements than you need, vitamin A will build up in your body.

It is unlikely that you will experience health problems from eating lots of vitamin-rich food. But in some rare cases, if you have lots of a particular food (such as very large quantities of carrot juice or liver), vitamin A might build up over time.

Further, if someone has too much beta-carotene, it can cause their skin to turn a yellow shade.

Can I take too much vitamin A?

It is possible to take too much vitamin A so be careful. Taking high doses of vitamin A over a long period of time can result in harmful levels in the body — unless you have a medically diagnosed deficiency.

There are some studies that show a link between beta-carotene supplements and an elevated risk of lung cancer in people who smoke cigarettes. The Cancer Council recommends that you avoid taking more than 19mg of beta-carotene supplements, especially if you smoke.