Iodine deficiency French, the term "crétin des Alpes" also became current, since the condition was observed in remote valleys of the Alps in particular. The word "cretin" appeared in English in 1779. While reporting recent progress towards overcoming iodine-deficiency disorders worldwide, "The Lancet" noted: "According to World Health Organization, in 2007, nearly 2 billion individuals had insufficient iodine intake, a third being of school age." A conclusion was made that the single most preventable cause of intellectual disability is that of iodine deficiency. There is preliminary evidence that iodine deficiency enhances the sensitivity of breast tissue to estrogen. In rats treated with
Fluorine deficiency Fluorine deficiency Fluoride or fluorine deficiency is a disorder which may cause increased dental caries (or tooth decay, is the breakdown of dental tissues by the acidic products released by the "bacterial fermentation of dietary carbohydrates.") and possibly osteoporosis (a bone disorder which leads to a decrease in bone mass, and an increase in bone fragility), due to a lack of fluoride in the diet. In terms of dietary sources, fish and tea are considered natural sources of fluoride, as well as tap water that has been fluoridated. The extent to which the condition truly exists, and its relationship to