Carrots are our most abundant source of beta carotenes, an antioxidant nutrient that the body converts to vitamin A. One large carrot provides 17mg of beta carotene and more than 6 times the Recommended Daily Allowance (RDA) of vitamin A, a nutrient essential for healthy hair, skin, eyes, bones, and mucous membranes. Vitamin A also helps prevent infections in the body. Antioxidants, such as beta carotene and vitamin A, are essential to the diet because they protect against cancer.
A recent government study found that research volunteers who ate 7 ounces (about 1 cup) of carrots a day had an average 11% reduction in their blood cholesterol levels after only 3 weeks.
Carrots will not prevent or correct our most common vision problems, such as myopia and farsightedness. but a deficiency of vitamin A does cause night blindness, an inability of the eyes to adjust to dim lighting or darkness. Vitamin A combines with the protein opsin in the retina's rod cells to form the substance (rhodopsin) that the eye needs for good night vision. Consuming just one carrot every few days will provide enough vitamin A to prevent or overcome night blindness.
Naturally sweet, carrots make an ideal high-fiber, low-calorie snack food. Cooking actually increases carrot's nutritional value, because it breaks down the tough cellular walls that encase the beta carotene. To convert beta carotene to vitamin A, the body needs at least a small amount of fat, because vitamin A is soluble in fat, not water. Serving cooked carrots with a small part of butter or margarine ensures that the body will be able to fully utilize this nutrient. Cooked and puréed carrots are an ideal beginner food, since they are naturally sweet and high in nutrients.
Carrots are also high in carotenoids, the yellow pigments that are the source of beta carotene and many flavonoids. Excessive intake of carrots may produce high levels of these pigments giving the skin a yellowish tinge. This harmless condition, called carotenemia, will disappear within a few weeks of reducing carrot consumption. If the yellow skin persists, however, or if the white portions of the eyes are also discolored, the problem may be jaundice, a symptom of a liver disease.