What is it? Overview Usage Side Effects and Warnings

What is Beta-Carotene?

Note:All the significant positive evidence for beta-carotene applies to food sources, not supplements.

Beta-carotene belongs to a family of natural chemicals known as carotenoids . Widely found in plants, carotenoids along with another group of chemicals, bioflavonoids, give color to fruits, vegetables, and other plants.

Beta-carotene is a particularly important carotenoid from a nutritional standpoint, because the body easily transforms it to vitamin A . While vitamin A supplements themselves can be toxic when taken to excess, it is believed (although not proven) that the body will make only as much vitamin A out of beta-carotene as it needs. Assuming this is true, this built-in safety feature makes beta-carotene the best way to get your vitamin A.

Beta-carotene is...

There are no well-documented therapeutic uses of beta-carotene, beyond supplying nutritional doses of vitamin A.

Numerous observational studies have found that a high intake of foods rich in carotenoids is associated with a lower incidence of lung cancer, other forms of cancer , and heart disease . 1 2 3 4 5 6 However, beta-carotene supplements have not been found to be helpful for preventing these conditions. 7 In fact, when all major beta-carotene studies are statistically combined through a process called “meta-analysis,” some evidence appears suggesting that long-term usage of beta-carotene at high doses might increaseoverall death rate, for reasons that are unclear. 8 Similarly, observational evidence links high dietary intake of carotenoids to...

Safety Issues

At recommended dosages, beta-carotene is believed to be very safe. The only side effects reported from beta-carotene overdose are diarrhea and a yellowish tinge to the hands and feet. These symptoms disappear once you stop taking beta-carotene or reduce your dose.

However, long-term use of beta-carotene supplements, especially at doses considerably above the amount necessary to supply adequate vitamin A, might slightly increase the risk of heart disease and certain forms of cancer, and raise overall death rate. 9 A large study following 77,126 adults over age 50 suggested that long-term use of beta-carotene, lutein or retinol supplements may increase lung cancer risk. Long-term supplement use was determined by subjects' memory of the previous 10 years, so the...