There is no universal agreement on how beta-carotene affects vision. Some studies that look at using beta-carotene to prevent cataracts have shown a lower risk, but others show no benefit. Beta-carotene has been shown to help treat an eye disease called age-related macular degeneration (AMD) when it is used with other medications.
Beta-carotene and vitamin A are important to help maintain skin and membrane linings. Proof that beta-carotene is important for skin and membrane health is based on studies of people with erythropoietic protoporphyria. This disorder can cause painful sensitivity to light. When beta-carotene is given to people with this condition, their tolerance to light increases.
Beta-carotene is safe for most people when taken within recommended amounts. Side effects may include diarrhea and yellow or orange skin discoloration. Rarely, bruising and joint or muscle pain may occur. Headaches have been reported in some cases.
Drug interactions associated with the use of beta-carotene supplements include:
- statins: When beta-carotene is used together with selenium, vitamin C, and vitamin E, it may decrease the effectiveness of simvastatin.
- niacin: When beta-carotene is used together with selenium, vitamin C, and vitamin E, it may reduce the effectiveness of niacin.
- orlistat: Orlistat can prevent the absorption of beta-carotene.
The following is a list of warnings and precautions related to the use of beta-carotene supplements.
- alcohol: High alcohol consumption may decrease the concentration of beta-carotene in the blood.
- allergic reactions: Beta-carotene should be avoided in individuals who are allergic to it or to any ingredients in the different formulations of products that contain beta-carotene.
- angioplasty: You should not use beta-carotene supplements before or after a heart procedure known as angioplasty.
- asbestos: You should not use beta-carotene supplements if you have a history of asbestos exposure.
- cigarette smoking: It is not recommended to use beta-carotene supplements if you smoke, as this may increase your risk of lung and prostate cancer.
- kidney disorders: If you have reduced kidney function, you should be careful in using beta-carotene.
- liver disease: If you have a liver disorder or disease, you should not use beta-carotene.
- pregnancy and breast-feeding: There is not currently enough evidence regarding the use of beta-carotene supplementation during pregnancy or breast-feeding.
Before taking any new medications, including natural health products, speak to your physician, pharmacist, or other health care provider. Tell your health care provider about any natural health products you may be taking.