Other name(s)

vitamin A, b-carotene, provitamin A

General

Beta-carotene is a type of substance called a carotenoid. Carotenoids give plants such as carrots, sweet potatoes, and apricots t heir reddish-violet colors.

Beta-carotene is a provitamin. This means it's used by your body to make vitamin A. It's only found in plants. Vitamin A is also found in foods from animals. Vitamin A from animal sources is called preformed. This means it is in a form your body can use directly. It's found in dairy products, fish oils, eggs, and meat (especially liver). The vitamin A your body makes from beta-carotene doesn’t build up in your body to toxic levels. But vitamin A from animal sources can. Vitamin A is available in multivitamins and as a stand-alone supplement. Vitamin A supplements can contain only beta-carotene, only preformed vitamin A, or a combination of both types of vitamin A.

If your body doesn't use all the beta-carotene you eat to make vitamin A, the beta-carotene that remains circulates in your body. Beta-carotene is also an antioxidant. It helps keep cells healthy.

Main functions

Beta-carotene and vitamin A play a vital part in the reproductive process. They also help keep skin, eyes, and the immune system healthy.

Demonstrated uses

Beta-carotene and other carotenoids help reduce free radical damage in your body.

Taking beta-carotene supplements can help you get enough vitamin A. These supplements are considered safe.

Reasons for increased need

Poor nutrition is a leading cause of beta-carotene and vitamin A deficiency. These problems can keep you from getting enough vitamin A:

• Lactose intolerance

• Sprue

• Cystic fibrosis

Women who are pregnant or breastfeeding may need to take supplements. Be sure to talk to your healthcare provider before doing this.

Claims

Beta-carotene may reduce the risk of some types of cancer, such as prostate cancer. But more research is needed to know the effects of vitamin A on other types of cancer.

It may reduce the risk of heart disease and stroke. But studies seem to show that neither beta-carotene nor vitamin A help prevent coronary heart disease.

One study found a higher risk of lung cancer in smokers and workers exposed to asbestos when they had more beta-carotene.

Recommended intake

There are no Dietary Reference Intakes for beta-carotene. The Recommended Dietary Allowance for vitamin A are noted below. They’re noted in micrograms (mcg) of retinol activity equivalents (RAE). They’re also noted in International Units (IUs).

Food sources

This table notes the IU of vitamin A in foods. It also notes the percentage of your daily value of vitamin A that the food meets.

Eating more fruits and vegetables can help you get more beta-carotene. Red, orange, deep yellow, and dark green produce tends to be high in carotenoids.

Signs of deficiency

Vitamin A deficiency can cause symptoms. These can include night blindness, fatigue, skin issues, and a weakened immune system. Severe vitamin A problems can lead to blindness. This is a leading cause of blindness in some parts of the world.

Toxicity

Beta-carotene doesn’t seem to be toxic in large doses. But high doses over a long time can lead to carotenemia. This causes your skin to become yellowish orange.

Too much beta-carotene is a problem for some people. This includes people who can't convert beta-carotene to vitamin A. This can happen to people who have hypothyroidism.

Higher doses of vitamin A may increase the risk for fractures in both women past menopause, and in men.

Interactions

Orlistat, a medicine for weight loss, decreases how well beta-carotene and vitamin E are absorbed. It’s unknown if it reduces absorption of vitamin A.

You should not use vitamin A or beta-carotene supplements if you take any of these medicines:

• Isotretinoin

• Acitretin

• Etretinate

Warfarin is a medicine used to slow blood clotting. Large amounts of vitamin A can slow blood clotting. Be sure to let your healthcare provider know if you are taking warfarin and vitamin A. You may need to have your blood clotting time checked more often. Your provider man need to change dose of your warfarin.