Beta-carotene is a carotenoid, one of a group of plant pigments known to have antioxidant and other effects. This is a substance in plants that's quickly converted into vitamin A inside the body. Beta-carotene is often thought of as a form of vitamin A itself. Having normal levels of vitamin A is key for good vision, strong immunity, and general health.
Why do people take beta-carotene?
Beta-carotene has become popular in part because it's an antioxidant -- a substance that may protect cells from damage. A number of studies show that people who eat lots of fruits and vegetables that are rich in beta-carotene and other vitamins and minerals have a lower risk of some cancers and heart disease. However, so far studies have not found that beta-carotene supplements have the same health benefits as foods.
Beta-carotene supplements may help people with specific health problems. Supplements might be used in someone with a clear vitamin A deficiency. They also might help those with the genetic condition erythropoietic protoporphyria (EPP). Both conditions are rare.
There's some promising evidence that beta-carotene supplements might slow the course of osteoarthritis. Taking beta-carotene along with zinc and vitamins C and E may also help reduce progression of age-related macular degeneration, a leading cause of blindness in older people.
Beta-carotene supplements have been studied as a treatment for many other diseases. Examples include cataracts, Alzheimer's disease, and cystic fibrosis. The results have been inconclusive.
How much beta-carotene should you take?
While there is a recommended dietary allowance (RDA) for vitamin A, there is no RDA for beta-carotene specifically. Studies have used dosages ranging between 15 and 180 milligrams a day.
There is no set tolerable upper intake level (UL) for beta-carotene. However, high doses or long-term use may be dangerous.
Many experts recommend a combination of supplemental carotenoids (lutein, carotenes, zeaxanthine, lycopene, etc), rather than simply beta-carotene. The correct dose of mixed carotenoids for temporary or long-term use is unclear.
Can you get beta-carotene naturally from foods?
The American Heart Association suggests that you get beta-carotene (and other antioxidants) from food rather than supplements. Good food sources of beta-carotene include:
- Sweet potatoes
- Winter squash
- Spinach and kale
- Fruits like cantaloupe and apricots
Beta-carotene levels are highest in fresh fruits and vegetables. Frozen and canned varieties generally have less.
What are the risks of taking beta-carotene?
- Side effects. Taken at the amounts found in foods, beta-carotene has few side effects. At high levels, it may turn the skin yellowish or orange. This is temporary and harmless.
- Risks. While their benefits are generally unclear, beta-carotene supplements do seem to have serious risks. People who smoke or who have been exposed to asbestos should not use beta-carotene supplements. Even low doses have been linked with an increased risk of cancer, heart disease, and death in these two groups of people. Excessive alcohol use combined with beta-carotene supplements may raise the risk of liver disease and cancer. In high doses, vitamin A, and presumably beta-carotene, can be toxic to the liver.
- Interactions. If you take any regular medications, ask your doctor if beta-carotene supplements are safe. They may interact with cholesterol drugs and other medicines.
Given the lack of evidence about their safety, children or women who are pregnant or breastfeeding should only take beta-carotene supplements if their doctors recommend it.