Beta-carotene, derived from the Latin name for carrot, belongs to a family of
natural chemicals known as carotenes or carotenoids. Widely found in plants,
carotenes give yellow and orange fruits and vegetables their rich colors.
Beta-carotene is also used as a coloring agent for foods such as margarine.
Beta-carotene is converted to vitamin A (retinol) by the body. While
excessive amounts of vitamin A in supplement form can be toxic, the body will
only convert as much vitamin A from beta-carotene as it needs. This feature
makes beta-carotene a safe source of vitamin A.
Like all other carotenoids, beta-carotene is an antioxidant. Consuming foods
rich in beta-carotene appears to protect the body from damaging molecules called
free radicals. Free radicals cause damage to cells through a process known as
oxidation, and over time, such damage can lead to a variety of chronic
illnesses. Some studies suggest that dietary intake of beta-carotene may reduce
the risk of two types of chronic illness—heart disease
and cancer. Supplementation, however, is more controversial; see discussion in
the section that follows.
Population-based studies suggest that groups of people who eat 4 or more
daily servings of fruits and vegetables rich in beta-carotene may have less of a
chance of developing heart disease or cancer. Interestingly, however, other
studies indicate that people who take beta-carotene supplements may actually be
at an increased risk for such conditions. Researchers speculate that multiple
nutrients, consumed in a healthy, balanced diet may be more effective than
beta-carotene supplements alone in protecting against cancer and heart disease.
Studies suggest that high doses of beta-carotene may decrease sensitivity to
the sun. This is particularly helpful for people with skin conditions caused by
sunlight exposure, such as erythropoietic protoporphyria, a condition
characterized, in part, by development of hives or eczema upon exposure to the
sun. Under the guidance of an appropriate health care professional, the oral
supplement dose of beta-carotene is slowly adjusted over a matter of weeks and
exposure to sunlight gradually increased.
Because people with scleroderma, a connective-tissue disorder characterized
by hardened skin, have low levels of beta-carotene in their blood, some
researchers speculate that beta-carotene supplements may be beneficial for those
with the condition. Due to methodological flaws in the studies that have been
conducted to date, however, research has not confirmed this theory. At this
time, it is best to obtain beta-carotene from dietary sources and avoid
supplementation until more information is available.
The richest sources of beta-carotene are yellow, orange, and green leafy
fruits and vegetables (such as carrots, spinach, lettuce, tomatoes, sweet
potatoes, broccoli, cantaloupe, and winter squash). In general, the greater the
intensity of the color of the fruit or vegetable, the more beta-carotene it
Dosage and Administration
Beta-carotene supplements are available in both capsule and gel forms.
Beta-carotene is fat-soluble and, therefore, should be taken with meals
containing at least 3 g of fat to ensure absorption.
For children younger than 14 with erythropoietic protoporphyria (see
Treatment section for brief
description of this condition), 30 to 150 mg per day (50,000 to 250,000 IU) in
single or divided oral doses for 2 to 6 weeks is recommended. The supplement may
be mixed with orange or tomato juice to facilitate administration. In the case
of this sun-sensitive condition, a doctor can measure blood levels of
beta-carotene and adjust the dose accordingly.
For general health, 15 to 50 mg (25,000 to 83,000 IU) per day is
For adults with erythropoietic protoporphyria, 30 to 300 mg (50,000 to
500,000 IU) per day for 2 to 6 weeks is recommended. A healthcare practitioner
can measure blood levels of beta-carotene and adjust the dose accordingly.
Beta-carotene offers protection from cancer only when other important
antioxidants, including vitamins C and E are present in the diet. Since
beta-carotene may increase the risk of heart disease and cancer in those who
smoke or drink heavily, this supplement should be used with caution, if at all,
by heavy smokers or drinkers.
Although beta-carotene affords protection from sunlight for people with
certain skin sensitivities, it does not protect against sunburn.
Side effects from beta-carotene include:
Skin discoloration (yellowing that eventually goes
Pregnancy and Breastfeeding
While animal studies indicate beta-carotene is not toxic to a fetus or a
newborn, there are no human studies to confirm these findings. The supplement
may pass into breast milk but no information on the safety of its use during
breastfeeding has been reported. Therefore, while pregnant or breastfeeding,
beta-carotene supplements should only be used under the guidance of a physician
or other appropriately trained specialist.
Side effects in children are the same as those seen in
Side effects in older adults are the same as younger
Interactions and Depletions
People taking the following medications should avoid beta-carotene
Cholestyramine, Colestipol, Probucol
Cholestyramine and probucol, medications used to lower cholesterol, can lower
blood concentrations of dietary beta carotene by 30% to 40%, according to a
3-year trial in Sweden. Colestipol, a cholesterol-lowering medication similar to
cholestyramin, may also reduce beta-carotene levels.
Beta-carotene and orlistat, a weight loss medication, should not be taken
together because orlistat can reduce the absorption of beta-carotene by as much
as 30%, thereby reducing the amount of this nutrient in the body. Those who must
take both orlistat and beta-carotene supplements should separate the time
between taking the medication and the supplements by at least 2 hours.
In addition to these medications, mineral oil (used to treat constipation)
may lower blood concentrations of beta-carotene and ongoing use of alcohol may
interact with beta-carotene, increasing the likelihood of liver
The Alpha-tocopherol, Beta-carotene Cancer Prevention Study Group. The effect
of vitamin E and Beta Carotene on incidence of lung cancer and other cancers in
male smokers. N Engl J Med. 1994;330:1029-1035.
Clark JH, Russell GJ, Fitzgerald JF, Nagamori KE. Serum beta-carotene,
retinol, and alpha-tocopherol levels during mineral oil therapy for
constipation. Am J Dis Child. 1987;141(11):1210-1212. (abstract)
DerMarderosian A. Ed. The Review of Natural Products. Tanning Tablets.
St. Louis, MO: Facts and Comparisons; 2000. [Date of issue Nov. 1991]
Elinder LS, Hadell K, Johansson J, Molgaard J, Holme I, Olsson AG, et al.
Probucol treatment decreases serum concentrations of diet-derived antioxidants.
Arterioscler Thromb Vasc Biol. 1995;15(8):1057-1063. (abstract)
Facts and Comparisons. Beta Carotene. Loose leaf edition. St. Louis:
Mo; Wolters Kluwer Co; Jan 2000 update:7.
Gabriele S, Alberto P, Sergio G, Fernanda F, Marco MC. Emerging potentials
for an antioxidant therapy as a new approach to the treatment of systemic
sclerosis. Toxicology. 2000; 155(1-3):1-15.
Hercberg S, Galan P, Preziosi P. Antioxidant vitamins and cardiovascular
disease: Dr Jekyll or Mr Hyde? Am J Public Health. 1999;
Herrick AL, Hollis S, Schofield D, Rieley F, Blann A, Griffin K, Moore T,
Braganza JM, Jayson MI. A double-blind placebo-controlled trial of antioxidant
therapy in limited cutaneous systemic sclerosis. Clin Exp Rheumatol.
Hu G, Cassano PA. Antioxidant nutrients and pulmonary function: the Third
National Health and Nutrition Examination Survey (NHANES III). Am J
Leo MA, Lieber CS. Alcohol, vitamin A, and beta-carotene: Adverse
interactions, including hepatotoxicity and carcinogenicity. Am J Clin
Liede KE, Alfthan G, Hietanen JH, Haukka JK, Saxen LM, Heinonen OP.
Beta-carotene concentration in buccal mucosal cells with and without dysplastic
oral leukoplakia after long-term beta-carotene supplementation in male
smokers. Eur J Clin Nutr. 1998;52(12):872-876.
Martindale: The Complete Drug Reference. 32nd edition. London,
UK; Pharmaceutical Press; 1999. Micromedex Inc., on line database.
Mathews-Roth MM. Photoprotection by carotenoids. Federation
McEvoy Ed. AHFS Drug Information. Bethesda, MD: American Society of
Health-System Pharmacists; 2000:3308.
Omenn GS, Goodman G, Thornquist M, Grizzle J, Rosenstock L, Barnhart S, et
al. The beta-carotene and retinol efficacy trial (CARET) for chemoprevention of
lung cancer in high risk populations. Smokers and asbestos exposed workers.
Cancer Res. 1994;54:2038S-2043S.
Omenn GS, Goodman GE, Thornquist MD, et al. Risk factors for lung cancer and
for intervention effects in CARET, the Beta-Carotene and Retinol Efficacy Trial.
J Natl Cancer Inst. 1996;88(21):1550-1559. [abstract]
Physician's Desk Reference. 54th ed. Montvale, NJ: Medical
Economics Company, Inc.; 2000:2695.
Pizzorno JE, Murray MT. Textbook of Natural Medicine, Vol 1.
2nd Edition. Edinburgh, UK: Churchill Livingstone; 1999.
Pryor WA, Stahl W, Rock CL. Beta carotene: from biochemistry to clinical
trials. [Review] Nutr Rev. 2000;58(2 Pt 1):39-53.
Roodenburg AJ, Leenen R, van het Hof KH, Weststrate JA, Tijburg LB. Amount of
fat in the diet affects bioavailability of lutein esters but not of
alpha-carotene, beta-carotene, and vitamin E in humans. Am J Clin Nutr.
Werbach M, Moss J. Textbook of Nutritional Medicine. Tarzana, Calif: Third
Line Press; 1999.
West KP, Katz J, Khatry SK, LeClerq SC, Pradhan EK, Shrestha SR, et al.
Double blind cluster randomised trial of low-dose supplementation with vitamin A
or beta carotene on mortality related to pregnancy in Nepal. The NNIPS-2 Study
Group. BMJ. 1999;318(7183):570-575. (Available online at:
Woutersen RA, Wolterbeek AP, Appel MJ, van den Berg H, Goldbohm RA, Feron VJ.
Safety evaluation of synthetic beta-carotene. [Review] Crit Rev Toxicol.
Review Date: March 2001
Reviewed By: Participants in the review process include: David Winston, Herbalist,
Herbalist and Alchemist, Inc., Washington, NJ; Jacqueline A. Hart, MD,
Department of Internal Medicine, Newton-Wellesley Hospital, Harvard University
and Senior Medical Editor Integrative Medicine, Boston,
The publisher does not accept any responsibility for the accuracy of
the information or the consequences arising from the application, use, or misuse
of any of the information contained herein, including any injury and/or damage
to any person or property as a matter of product liability, negligence, or
otherwise. No warranty, expressed or implied, is made in regard to the contents
of this material. No claims or endorsements are made for any drugs or compounds
currently marketed or in investigative use. This material is not intended as a
guide to self-medication. The reader is advised to discuss the information
provided here with a doctor, pharmacist, nurse, or other authorized healthcare
practitioner and to check product information (including package inserts)
regarding dosage, precautions, warnings, interactions, and contraindications
before administering any drug, herb, or supplement discussed