beta carotene


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carotene

 [kar´o-tēn]
a yellow or red pigment found in many dark green, leafy, and yellow vegetables such as collards, turnips, carrots, sweet potatoes, and squash, as well as in yellow fruit, milk, egg yolk, and body fat; it is a chromolipoid hydrocarbon existing in four forms (α-, β-, γ-, and δ-carotene), which can be converted into vitamin A in the body.
beta carotene
1. the β isomer of carotene.
2. a preparation of this substance administered orally to prevent vitamin A deficiency and to reduce photosensitivity in patients with erythropoietic protoporphyria. Written also betacarotene and β-carotene.

beta carotene

also

beta-carotene

(bā′tə-kăr′ə-tēn′, bē′-)
n.
The isomeric form of carotene that is most widely distributed in nature and is efficiently converted to vitamin A by the body.

beta carotene

A yellow-orange pigment found in fruits and vegetables; it is the most common precursor of vitamin A. The daily human requirement for vitamin A can be met by dietary intake of beta carotene.

Toxicity

Ingestion of large doses of vitamin A either acutely or chronically causes skin and liver damage, among other injuries. Beta carotene supplements increase the risk of death among smokers and have no known beneficial effects on nonsmokers. Beta carotene occurring naturally in foods has no known toxicity.

Benefits

A diet rich in beta carotene has been associated with a decreased risk of certain cancers.

Dosing

Vitamin A activity in foods is expressed as retinol equivalents (RE). Six mg of beta carotene equals 1 µg of retinol or 1 RE.

See: vitamin A; retinol

beta carotene

A precursor of vitamin A.
References in periodicals archive ?
Beta carotene has been thought of value to humans and other species because of excellent antioxidant properties9 and has been shown to guard against APAP-induced hepatic damage cancers and heart diseases1012.
The amount of beta carotene in roots stored under different conditions tended to increase in the first month of storage.
The study involved 7,641 male physicians from the Physicians' Health Study I, who had begun taking beta carotene or placebo in 1982, plus 7,000 new recruits age 50 and over, whose randomization began in 1997.
In another study, over 22,000 male physicians aged 40 to 84 were randomly assigned to receive either beta carotene or a placebo from 1984 to 1995.
It is a gold mine of beta carotene with the squash and carrots and also contains calcium and minerals from the yogurt and lots of vitamin C from the fresh lime juice.
As beta carotene has clearly no benefit and even a hint of possible harm, I can see no reason that people should take it," comments National Cancer Institute director Richard Klausner.
Research shows that the antioxidant beta carotene possesses "cancer preventing compounds," according to Dr.
More than 29,000 middle-aged male smokers, divided into four groups, were given beta carotene (20 milligrams daily) alone, vitamin E (50 milligrams) alone, both nutrients, or a placebo for an average of six years.
Of these nutrients, beta carotene has received the most attention of late, and some manufacturers of dietary supplements containing beta carotene have been promoting these products as possible cancer preventives.
Paul Knekt of the Social Insurance Institution, Helsinki, reported recently on studies supporting the hypothesis that foods rich in vitamin C, vitamin E, and beta carotene may help prevent cancer.
Softgel Combines Strongest Ocean Spray Cranberry Extract with Vitamin C, Beta Carotene and Selenium in Low Calorie2 Formula that Offers Maximum Urinary Tract Support
Objective: To study the protective role of beta carotene against acetaminophen-induced hepatotoxicity in rats.