Beta-Carotene

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, their reddish-violet colors.

Beta-carotene is a provitamin. This means it's used by your body to make vitamin A. Provitamin A is only found in plants. Vitamin A is also found in foods from animals. Vitamin A from animal sources is called preformed vitamin A. 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. It's also available 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

• Celiac disease (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 Allowances 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 include:

• Night blindness

• Fatigue

• Skin issues

• 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.

High dose supplements with preformed vitamin A are not advised during pregnancy. Too much may cause birth defects or miscarriage.

Interactions

Orlistat, a medicine for weight loss, decreases fat absorption in the body. Because of this, it may also reduce absorption of beta-carotene and vitamin A. Vitamin A is a fat-soluble vitamin.

Don't use vitamin A or beta-carotene supplements if you take any of these medicines. This is because they contain derivatives of vitamin A:

• Isotretinoin

• Acitretin

• Etretinate