Beta-Carotene is an organic compound that gives color to plants and fruits. It is also used for food coloring, it has the E number E160a . Beta-carotene is the most well-known provitamin A carotenoid (precursor to vitamin A), which means body turns beta-carotene into the antioxidant vitamin A (via beta-carotene 15,15′-monooxygenase) .
Beta-Carotene is being used as an oral sun protectant, and evidence indicates that carotenoids may protect human skin from light-induced lesions.  Biesalski et al.  have speculated that carotenoids contribute to protection against acute and chronic exposure to UV light. However, little is known about distribution and accumulation of beta-carotene in tissues.
Satoshi and colleagues  have reported that 30 mg of beta-carotene per day for 1 month may favorably affect exercise-induced oxidative DNA damage.
Beta-carotene is also used to decrease asthma symptoms caused by exercise, probably through in vivo antioxidative effect .
Is beta-carotene anticarcinogenic?
The risks of cancer and heart diseases are lowered by consumption of leafy vegetables rich in beta-carotene. Some earlier studies note that beta-carotene, may reduce the risk of chronic disease, such as coronary heart disease, certain cancers and cataract . However, according to WebMd.com: “studies show beta-carotene supplements don’t lessen cancer or heart disease risks in healthy adults and may raise the risk of lung cancer in smokers and people exposed to asbestos.” 
The effectiveness of beta-carotene for treating different forms of cancer is still debated and has currently not been proven to prevent cancer in humans . However, beta-carotene is used for breast cancer prevention although there are currently no known studies that support its use for lowering breast cancer risk .