Why would a person crave raw carrots and the cause a problem if eaten in excess?

Raw carrot craving: I've run across a few reports of craving raw carrots in pregnancy. Also there was one report in british journal of addiction -- series of 3 patients who couldn't stop eating the carrots. They described their addiction as similar to cigarettes. See the abstract: http://www.Ncbi.Nlm.Nih.Gov/pubmed/1511232 if you eat enough carrots, the carotenoids could turn your skin yellow-orange.