Beta-carotene

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Beta-carotene may reduce risk of heart disease and cancer. Beta-carotene supplementation, however, may be dangerous. Learn about the usage, dosage, side-effects of beta-carotene.

Common Forms: b-carotene, Trans-beta Carotene, Provitamin A, Betacarotenum

Overview

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.

Therapeutic Uses

Prevention

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.

Treatment

Sun Sensitivity

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.

Scleroderma

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.

Dietary Sources of Beta-carotene

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 contains.

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.