Vitamins, Minerals and Dietary Supplements
What is beta carotene?
Beta carotene is an antioxidant, a substance that minimizes the damage to the body caused by free radicals. It is present in plants (giving them their pigment), and is converted by the body into vitamin A.
In addition to its naturally occurring form, some manufacturers also make synthetic beta carotene, but this form should probably be avoided until research can prove its effectiveness.
Studies have shown that beta carotene can protect the body from developing a variety of harmful conditions. It may help improve vision in some people with poor sight, and help people who suffer from night blindness. It also boosts the immune system, and can help the body fight off infections. Specifically, beta carotene can guard against heart disease, and prevent certain forms of cancer and many precancerous conditions. Research using natural beta carotene has shown that it can help prevent the symptoms of asthma in some people while performing exercise. Synthetic beta carotene does not appear to have antioxidant properties.
How much beta carotene should I take?
The typical beta carotene supplement contains approximately 25,000 international units, or 15 milligrams. Some people may take amounts as high as 60 mg per day. It can be obtained by eating certain types of vegetables or supplements.
What forms of beta carotene are available?
Beta carotene can be found in dark green and orange-yellow vegetables such as carrots, cantaloupe and broccoli. For green vegetables, the darker the color, the higher the level of beta carotene present.
What can happen if I take too much beta carotene? Are there any interactions I should be aware of? What precautions should I take?
Because the body excretes any beta carotene that it doesn’t use, it is virtually impossible to overdose on it. However, patients who take extremely high amounts of beta carotene for extended periods of time may experience a yellowing or orange tint to the skin, particularly on the soles of the feet and the palms of the hands. If this occurs, consult a health care provider; the color will eventually fade with decreased beta carotene intake.
Research has shown that beta carotene supplements may actually increase the risk of lung cancer in smokers. As such, beta carotene, either in natural or synthetic form, should not be consumed by smokers, and synthetic forms of the substance should be avoided altogether. Animal research suggests that beta carotene, combined with heavy alcohol consumption, may cause liver damage; therefore, alcoholics or people who take alcohol on a daily basis should not take beta carotene supplements. As always, make sure to consult with a licensed health care provider before taking beta carotene or any other dietary supplement or herbal remedy.
- Hennekens CH, Burning JE, Manson JE, et al. Lack of effect of long-term supplementation with beta carotene on the incidence of malignant neoplasms and cardiovascular disease. New England Journal of Medicine 1996;334:1145-9.
- Lee IM, Cook NR, Manson JE, et al. Beta-carotene supplementation and incidence of cancer and cardiovascular disease: The Women’s Health Study. Journal of the National Cancer Institute 1999;91:2102-6.
- Leo MA, Lieber CS. Alcohol, vitamin A, and beta-carotene: adverse interactions, including hepatotoxicity and carcinogenicity. American Journal of Clinical Nutrition 1999;69:1071-85.
- Neuman I, Nahum H, Ben-Amotz A. Prevention of exercise-induced asthma by a natural isomer mixture of beta-carotene. Ann Allergy Asthma Immunol 1999;82:549-53.
- Omenn GS, Goodman GE, Thornquist MD, et al. Effects of a combination of beta carotene and vitamin A on lung cancer and cardiovascular disease. New England Journal of Medicine 1996;334:1150-5.