Nutrition

The carrot gets its characteristic and bright orange colour from β-carotene, which is metabolised into vitamin A in humans when bile salts are present in the intestines.^[3] Massive overconsumption of carrots can cause carotenosis, a benign condition in which the skin turns orange. Carrots are also rich in dietary fibre, antioxidants, and minerals.

Lack of Vitamin A can cause poor vision, including night vision, and vision can be restored by adding Vitamin A back into the diet. An urban legend says eating large amounts of carrots will allow one to see in the dark. The legend developed from stories of British gunners in World War II who were able to shoot down German planes in the darkness of night. The legend arose during the Battle of Britain when the RAF circulated a story about their pilots' carrot consumption as an attempt to cover up the discovery and effective use of radar technologies in engaging enemy planes, as well as the use of red light (which does not destroy night vision) in aircraft instruments.^[4][5] It reinforced existing German folklore and helped to encourage Britons—looking to improve their night vision during the blackouts—to grow and eat the vegetable.
Ethnomedically, the roots are used to treat digestive problems, intestinal parasites, and tonsillitis or constipation.

The wild ancestors of the carrot are likely to have come from Afghanistan, which remains the centre of diversity of D. carota, the wild carrot. Selective breeding over the centuries of a naturally occurring subspecies of the wild carrot, Daucus carota subsp. sativus reducing bitterness, increasing sweetness and minimizing the woody core, has produced the familiar garden vegetable.^[6][7]
In early use, carrots were grown for their aromatic leaves and seeds, not their roots. Some relatives of the carrot are still grown for these, such as parsley, fennel, dill and cumin. The first mention of the root in classical sources is in the 1st century CE. The modern carrot appears to have been introduced to Europe in the 8-10th centuries.^{[citation needed]} The 12th c. Arab Andalusian agriculturist, Ibn al-'Awwam, describes both red and yellow carrots; Simeon Seth also mentions both colours in the 11th century. Orange-coloured carrots appeared in the Netherlands in the 17th century.^[8] These, the modern carrots, were intended by the antiquary John Aubrey (1626–1697) when he noted in his memoranda "Carrots were first sown at Beckington in Somersetshire Some very old Man there [in 1668] did remember their first bringing hither."^[9]
In addition to wild carrot, these alternative (mostly historical) names are recorded for Daucus carota: Bee's-nest, Bee's-nest plant, Bird's-nest, Bird's-nest plant, Bird's-nest root, Carota, Carotte (French), Carrot, Common carrot, Crow's-nest, Daucon, Dawke, Devil's-plague, Fiddle, Gallicam, Garden carrot, Gelbe Rübe (German), Gingidium, Hill-trot, Laceflower, Mirrot, Möhre (German), Parsnip (misapplied), Queen Anne's lace, Rantipole, Staphylinos, and Zanahoria.



 http://en.wikipedia.org/wiki/Carrot