Carrots are good for the skin because of their high vitamin A and beta-carotene content. The U.S. Department of Agriculture reports that 1 cup provides 16,679 International Units of beta-carotene, which is equivalent to about 686 percent of the recommended daily dose for vitamin A. It’s important to understand the relationship of vitamin A to beta-carotene for general health reasons as well as for considerations regarding the condition of your skin.
While vitamin A represents a group of compounds, two basic forms are found in nature: preformed and provitamin A. Preformed vitamin A is found in animal sources and the "Journal of Clinical Nutrition" reports that it is efficiently absorbed and utilized by humans at absorption rates of 70 to 90 percent. The researchers express concern because intake of preformed vitamin A often exceeds the recommended dietary allowance for adults, especially in developed countries. Concern is heightened over the fact preformed vitamin A is fat soluble and stores in fat cells. Swedish researchers linked high levels to bone loss and fractures.
Beta-carotene is a form of provitamin A that’s converted into vitamin A by the body as a product of metabolism. Because beta-carotene is water soluble, the body converts what it needs from plant sources and excretes any excess. Numerous studies have shown that dietary beta-carotene is effective against ultraviolet radiation damage. The journal "Photochemistry and Photobiology" reports that 10 weeks of beta-carotene supplementation provides an SPF of 4 and that every additional month of supplementation increases protection.
Numerous studies have concluded that dietary and vitamin A supplementation is effective as a treatment against chronic hand eczema. The "British Journal of Dermatology" reports that a medication made from condensed vitamin A named alitretinoin, which is normally used to treat skin lesions, also cures chronic hand eczema. "Dermatologic Surgery" reports that vitamin A supplementation is effective in reducing tumors in patients with nonmelanoma skin cancer.
There are popular stories about people’s skin turning orange from eating too many carrots and many people wonder if the stories are true. They are, and the "International Journal of Food Sciences and Nutrition" reports that overindulgence can turn your skin and the whites of your eyes to tints of orange and yellow. Researchers determined that ingesting 20 milligrams of beta-carotene per day, which is the equivalent of three 8-inch carrots, is sufficient to pose a risk.
- USDA: Nutrient Data Laboratory
- American Journal of Clinical Nutrition; The Acute and Chronic Toxic Effects of Vitamin A; K. Penniston, et al.
- Photochemistry and Photobiology; Protection From Sunburn With Beta-carotene; W. Kopcke, et al.
- British Journal of Dermatology; Alitretinoin in Severe Chronic Hand Eczema; R. Bissonnette, et al.
- Dermatologic Surgery; Chemoprevention of Nonmelanoma Skin Cancer; C. Otley, et al.
- International Journal of Food Sciences and Nutrition; Studies on Hypercarotenemia; N. Wageesha, et al.