Beta-Carotene

Introduction

  • Beta-carotene is one of a group of red, orange, and yellow pigments called carotenoids.
  • Beta-carotene and other carotenoids provide approximately 50% of the vitamin A needed in the diet.
  • Beta-carotene is converted to vitamin A, an essential nutrient.
  • Vitamin A antioxidant activity, which helps to protect cells from damage
  • Beta-carotene can be found in fruits, vegetables, and whole grains. It can also be made in a laboratory.
  • Beta-carotene supplements are available in two forms. One is water-based, and the other is oil-based.
  • Studies show that the water-based version seems to be absorbed better

Other names

  • A-Bêta-Carotène
  • Beta Carotene
  • Bêta-Carotène Tout Trans
  • Beta-Caroteno
  • Carotenes
  • Carotenoids
  • Caroténoïdes Mélangés
  • Mixed Carotenoids
  • Provitamin A

Health Benefits

  • Beta-carotene may prevent:
  • Certain cancers
  • Heart disease
  • Cataracts
  • Age related macular degeneration (AMD)
  • Night blindness during pregnancy
  • Diarrhea and fever after giving birth
  • Sunburn easily in patients with an inherited disease called erythropoietic protoporphyria (EPP)
  • Vision loss and worsening of AMD in people with advanced AMD
  • Breast cancer
  • Complications of COPD (chronic obstructive pulmonary disease)
  • Worsening of osteoarthritis
  • Ovarian cancer in women after menopause
  • Toxic effects in children undergoing chemotherapy for a blood cancer called lymphoblastic leukemia
  • Esophageal cancer
  • Stomach cancer

  • Beta-carotene may benefit patients with:
  • AIDS
  • Alcoholism
  • Alzheimer’s disease
  • Chronic fatigue syndrome (CFS)
  • Compromised physical performance and muscle strength
  • Depression
  • Epilepsy
  • Exercise – induced asthma
  • Headaches
  • Heartburn
  • High blood pressure
  • Infertility
  • Malnutrition during pregnancy
  • Parkinson’s disease
  • Psoriasis
  • Rheumatoid arthritis
  • Schizophrenia
  • Vitiligo
  • Defective mental performance (thinking skills & memory)
  • Sun – induced polymorphous light eruptions

Safety

  • Beta-carotene is likely safe in adults and children when taken by mouth in appropriate amounts for certain specific medical conditions.
  • Beta-carotene supplements are not recommended for general use.
  • Beta-carotene is may not be safe when taken by mouth in high doses, especially when taken long-term.
  • High doses of beta-carotene can turn skin yellow or orange.
  • There is growing concern that taking high doses of antioxidant supplements such as beta-carotene might do more harm than good.
  • Some research shows that taking high doses of beta-carotene supplements might increase the chance of death from all causes, increase the risk of certain cancers, and possibly other serious side effects.
  • There is also concern that taking large amounts of a multivitamin plus a separate beta-carotene supplement increases the chance of developing advanced prostate cancer in men.

Overdose

  • β-Carotene, a precursor form of vitamin A typical of vegetable sources such as carrots, is selectively converted into retinoids, so it does not cause hypervitaminosis A
  • Overconsumption can cause carotenosis, a benign condition in which the skin turns orange.
  • The proportion of carotenoids absorbed decreases as dietary intake increases.
  • Within the intestinal wall (mucosa), β-carotene is partially converted into vitamin A (retinol) by an enzymedioxygenase.
  • This mechanism is regulated by the individual's vitamin A status. If the body has enough vitamin A, the conversion of β-carotene decreases.
  • Therefore, β-carotene is a very safe source of vitamin A and high intakes will not lead to hypervitaminosis A.
  • Excess β-carotene is predominantly stored in the fat tissues of the body.
  • The adult's fat stores are often yellow from accumulated carotene while the infant's fat stores are white.
  • Excessive intake of β-carotene leads to yellowish skin, but this is quickly reversible upon cessation of intake.

Precautions & Warnings

Pregnancy and breast-feeding

  • Beta-carotene is likely safe when taken by mouth in appropriate amounts.
  • Large doses of beta-carotene supplements are not recommended for general use during pregnancy and breast-feeding.

    Smoking
  • In smokers, beta-carotene supplements might increase the risk of colon, lung, and prostate cancer.
  • Don’t take beta-carotene supplements if you smoke.

    History of asbestos exposure
  • In previous exposure to asbestos, beta-carotene supplements might increase the risk of cancer.
  • Don’t take beta-carotene supplements if you have been exposed to asbestos.

    Angioplasty (a heart procedure)
  • There is some concern that when antioxidant vitamins, including beta-carotene, are used together they might have harmful effects after angioplasty.
  • They can interfere with healing.
  • Don’t use beta-carotene and other antioxidant vitamins before or after angioplasty without the recommendation of your healthcare provider.

Interactions with medications

Statins (Medications used for lowering cholesterol)

  • Taking beta-carotene, selenium, vitamin C, and vitamin E together might decrease the effectiveness of some medications used for lowering cholesterol.
  • It is not known if beta-carotene alone decreases the effectiveness of some medications used for lowering cholesterol.
  • Some medications used for lowering cholesterol include atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Mevacor), and pravastatin (Pravachol).

Niacin

  • Taking beta-carotene along with vitamin E, vitamin C, and selenium might decrease some of the beneficial effects of niacin.
  • Niacin can increase the good cholesterol.
  • Taking beta-carotene along with these other vitamins might decrease the good cholesterol.

Interactions with herbs and supplements

  • There are no known interactions with herbs and supplements.

Interactions with foods

Alcohol

  • Drinking excessive amounts of alcohol can reduce the level of beta-carotene in the body and increase the level of another chemical called retinol.
  • Researchers are concerned that this might increase the risk of cancer.
  • But more research is needed to find out whether this concern is justified.

Olestra (fat substitute)

  • Olestra may interfere with the action of beta-carotene in the body.
  • Olestra lowers serum beta-carotene concentrations in healthy people by 27%.

Recommended Dosage

The following doses have been studied in scientific research:

Erythropoietic protoporphyria (EPP)

  • Daily dosage is based on age.
  • Age 1 to 4: 60-90 mg
  • Age 5 to 8 years: 90-120 mg
  • Age 9 to 12 years: 120-150 mg
  • Age 13 to 16 years: 150-180 mg
  • Age 16 and older: 180 mg.
  • If people still remain too sensitive to the sun using these doses, beta-carotene can be increased by 30-60 mg per day for children under 16 years old, and up to a total of 300 mg per day for people older than age 16.
  • Prevention of sunburn in sun-sensitive people
    • Beta-carotene: 25 mg daily.
    • Treatment of age-related macular degeneration (AMD)
    • Beta-carotene: 15 mg plus vitamin C 500 mg, zinc oxide 80 mg, and vitamin E 400 IU daily.

    The recommended daily intake of beta-carotene has not been set because there hasn’t been enough research.

    Conversion factors

    • Since 2001, the US Institute of Medicine uses retinol activity equivalents (RAE) for their Dietary Reference Intakes, defined as follows:

    Retinol activity equivalents (RAEs)

    1 µg RAE = 1 µg retinol

    1 µg RAE = 2 µg all-trans-β-carotene from supplements

    1 µg RAE = 12 µg of all-trans-β-carotene from food

    1 µg RAE = 24 µg α-carotene or β-cryptoxanthin from food

    • Retinol activity equivalent (RAE) takes into account carotenoids' variable absorption and conversion to vitamin A by humans better than and replaces the older retinol equivalent (RE) (1 µg RE = 1 µg retinol, 6 µg β-carotene, or 12 µg α-carotene or β-cryptoxanthin). 
    • RE was developed 1967 by the United Nations/World Health Organization Food and Agriculture Organization (FAO/WHO).
    • Another older unit of vitamin A activity is the international unit (IU).
    • Like retinol equivalent, the international unit doesn't take into account carotenoids' variable absorption and conversion to vitamin A by humans as well as the more modern retinol activity equivalent.
    • Unfortunately, food and supplement labels still generally use IU, but IU can be converted to the more useful retinol activity equivalent as follows:

    International Units

    1 µg RAE = 3.33 IU retinol

    1 IU retinol = 0.3 μg RAE

    1 IU β-carotene from supplements = 0.15 μg RAE

    1 IU β-carotene from food = 0.05 μg RAE

    1 IU α-carotene or β-cryptoxanthin from food = 0.025 μg RAE1



    Carotene content per serving

    Item

    Grams per serving

    Serving size

    Milligrams β-carotene per serving

    Milligrams β-carotene per 100 g

    Carrot juice, canned

    236

    1 cup

    22.0

    9.3

    Pumpkin, canned, without salt

    245

    1 cup

    17.0

    6.9

    Sweet potato, cooked, baked in skin, without salt

    146

    1 potato

    16.8

    11.5

    Sweet potato, cooked, boiled, without skin

    156

    1 potato

    14.7

    9.4

    Spinach, frozen, chopped or leaf, cooked, boiled, drained, without salt

    190

    1 cup

    13.8

    7.2

    Carrots, cooked, boiled, drained, without salt

    156

    1 cup

    13.0

    8.3

    Spinach, canned, drained solids

    214

    1 cup

    12.6

    5.9

    Sweet potato, canned, vacuum pack

    255

    1 cup

    12.2

    4.8

    Carrots, frozen, cooked, boiled, drained, without salt

    146

    1 cup

    12.0

    8.2

    Collards, frozen, chopped, cooked, boiled, drained, without salt

    170

    1 cup

    11.6

    6.8